DEV Community: Farhan Shaikh

How to Set Up Email Notifications in Coolify with Reloop SMTP

Farhan Shaikh — Tue, 13 Oct 2026 17:37:45 +0000

Coolify can email you when a deployment fails, a backup breaks, or a server goes offline — but only after you give it a way to send mail. This guide walks through connecting Coolify’s email notifications to Reloop’s SMTP relay. It takes about ten minutes, and the free tier covers everything a Coolify instance will ever send.

By the end you will have a working Notifications > Email channel, a test email in your inbox, and the option to share one configuration across every team on your instance.

What Coolify email notifications do

Coolify runs your apps, databases, backups and cron jobs unattended. Notifications are how it tells you when something happened that you’d want to know about: a deployment succeeded or failed, a scheduled backup errored, a container stopped, a server stopped responding, or disk usage crossed a threshold.

Email is one of several notification channels (alongside Discord, Telegram, Slack, Pushover and webhooks). It’s the channel most teams start with, because every team already has an inbox and nothing else needs installing.

The catch is that Coolify has no mail server of its own. It has to hand each message to a provider that can deliver it, and you have to tell it which one. The team-level Notifications > Email page offers four options:

Hosted email service
System-wide settings
SMTP server
Resend

If you self-host — which is most Coolify users — the hosted option isn’t there, and you need to bring a provider. Reloop plugs into the SMTP server option, and this guide covers both the per-team setup and the instance-wide one.

Prerequisites

A running Coolify instance (self-hosted or Cloud) where you’re an admin of the team you want to configure.
A Reloop account — the free tier (3,000 emails/month).
A domain you control, so you can add DNS records for it.
Outbound port 587 open from the Coolify server. Most VPS providers allow it; if you’re on a provider that blocks all outbound SMTP you’ll see a connection timeout in step 4.

Step 1: Verify a domain and create an API key in Reloop
Reloop will only send from a domain you’ve proved you own. Do this part first; the SMTP login succeeds regardless, but mail from an unverified domain is rejected at send time.

In the Reloop dashboard, open Domains and add the domain you’ll send from (for example alerts.yourdomain.com or just yourdomain.com).
Add the DNS records Reloop shows you — SPF, DKIM and a DMARC record — at your DNS provider. Propagation usually takes a few minutes, occasionally up to an hour.
Wait for the domain to show as Verified.
Open API keys and create a key. Give it a name you’ll recognise later, like coolify-notifications. Copy it now — it's shown once.

You’ll use the API key as the SMTP password in the next step.

Step 2: Configure SMTP in Coolify
In Coolify, open your team’s Notifications page and select Email. The section is titled Email delivery.

Under Email service, choose Use team email settings. (On self-hosted instances the other option is Use system-wide settings; see step 3 if you’d rather set it once for every team.)
Fill in From name and From address before anything else. Both are required, and Coolify will refuse to enable SMTP while either is empty. The address must be on the domain you verified in step 1 — for example coolify@alerts.yourdomain.com.
Under SMTP delivery, enter the relay details:

Step 3 (optional): Set it once for the whole instance
If you self-host and have more than one team, you don’t want to paste the same API key into each one. Coolify lets the instance admin configure a single transactional email provider that every team can reuse.

Open Settings > Email (you need to be an instance admin, not just a team admin).
Enter the same sender and SMTP values from step 2, enable SMTP, and save.
Use Send Test Email on that page and confirm it arrives before going further.
Back in each team’s Notifications > Email, set Email service to Use system-wide settings.

Step 4: Choose events and send a test
Still on Notifications > Email, scroll to Notification settings. Events are grouped under Deployments, Resources, Backups, Scheduled tasks and Server. A sensible starting set:

Deployments: failed (successful deploys get noisy fast)
Backups: failed
Scheduled tasks: failed
Server: unreachable, disk usage threshold

Then select Send test at the top of the page, enter an address you can check, and send. The message should arrive within a few seconds. If it lands in spam the first time, that’s normal for a brand-new sending domain; mark it as not spam and later messages will land in the inbox.

You can also see the message in the Reloop dashboard under Logs, with the delivery status and the raw headers — useful when you’re not sure whether Coolify sent anything at all.

The 5 Best AI Agent Email Providers in 2026

Farhan Shaikh — Mon, 12 Oct 2026 10:36:43 +0000

AI agents are moving beyond chat interfaces.

Today, an AI agent can qualify leads, handle customer support, schedule meetings, process invoices, send follow-ups, and communicate with customers. But once an agent needs to communicate through email, a basic email-sending API is often not enough.

AI agents need to send emails, receive replies, understand threads, process attachments, trigger workflows, and act on incoming messages.

That is where AI agent email providers come in.

In this guide, we’ll compare the 5 best AI agent email providers in 2026, including their strengths, limitations, ideal use cases, and what to consider before choosing one.

The 5 best AI agent email providers

Reloop — Best open-source email infrastructure for AI agents.
AgentMail — Best for dedicated AI-agent inboxes.
Nylas — Best for connecting AI agents to existing inboxes.
Mailgun — Best for programmable inbound and outbound email.
Resend — Best for simple outbound email from AI applications.

The right provider depends on what your agent actually needs.

If your AI agent needs its own inbox and can autonomously receive, parse, and respond to email, you should prioritize agent-native infrastructure.

If your application only needs to send AI-generated notifications or reports, a traditional transactional email API may be enough.

Let’s look at each option.

What is an AI agent email provider?
An AI agent email provider gives developers the infrastructure required for an AI agent to communicate through email programmatically.

A traditional transactional email API is primarily designed around sending messages such as:

Password resets
Verification emails
Order confirmations
Receipts
Notifications
Product updates

An AI agent often needs considerably more.

For example, imagine a customer support agent receiving this email:

“My order #28391 hasn’t arrived. Can you check the status or issue a. refund?”

The agent needs to:

Receive the email
Understand the customer’s request
Extract the order ID
Determine the request type
Retrieve information from another system
Decide what action to take
Draft a response
Send the response
Maintain the conversation context if the customer replies

That means an AI agent email platform needs to handle more than outbound delivery.

It may need inbound email, mailboxes, threading, structured parsing, webhooks, attachments, authentication, deliverability, and developer APIs.

1. Reloop
Best for: Open-source AI agent email infrastructure

Reloop is an open-source email infrastructure platform designed for developers and AI agents.

Unlike traditional transactional email providers that primarily focus on sending messages, Reloop provides a dedicated AI Agent Inbox for agents that need to read, process, and respond to email.

Reloop supports the broader email infrastructure needed by AI applications, including transactional email, inbound email, webhooks, structured parsing, attachments, and email automation.

Why Reloop stands out for AI agents:

One of the biggest challenges when connecting email to an LLM is converting messy email data into something an agent can actually use.

Reloop addresses this with structured schema validation.

Developers can define a JSON schema for the information their agent needs. Incoming email can then be parsed and validated into structured data before it reaches the agent.

For example, a support agent could define fields such as:

{
  "orderId": "string",
  "requestType": "refund | tracking_status | general",
  "customerSentiment": "happy | neutral | angry"
}

Instead of forcing your application to parse raw MIME content, the agent receives structured information that can be passed directly into its workflow.

Reloop AI agent features:

Reloop’s AI-agent infrastructure includes:

Dedicated AI agent inboxes
Structured JSON schema validation
Inbound email processing
Thread context synchronization
Asynchronous agent webhooks
Attachment handling
Spam filtering
AI-oriented guardrails
Programmatic replies
Human-in-the-loop workflows
Hosted or self-hosted deployment

Reloop also states that its agent infrastructure provides average context stitching below 15ms and type-safe JSON validation for parsed email.

Open-source and self-hostable:

Another major difference is that Reloop is open source.

You can use Reloop as a hosted service or deploy the platform yourself using infrastructure such as Docker, Kubernetes, or bare metal.

That gives engineering teams more control over their email infrastructure and reduces dependence on a proprietary email vendor.

Reloop also supports multiple programming languages, including Node.js, Python, Go, Rust, PHP, Ruby, Elixir, Java, and .NET.

Best use cases for Reloop:

Reloop is a strong option for:

AI customer support agents
AI sales agents
Recruiting agents
Invoice-processing agents
Operations agents
Autonomous email assistants
Human-in-the-loop workflows
Applications requiring inbound email
Teams that want open-source infrastructure
Companies that need self-hosting

2. AgentMail
Best for: AI agents that need dedicated email identities and inboxes.

AgentMail is purpose-built around the idea that an AI agent can have its own email inbox.

The platform allows developers to programmatically create inboxes and lets agents send, receive, search, and reply to email.

This makes it particularly useful when an agent needs to behave like an independent participant in an email conversation.

For example, a recruiting agent could have:
recruiting-agent@company.com

The agent can then communicate with candidates, receive replies, and continue conversations from the same identity.

Why choose AgentMail?
AgentMail is designed around agent-owned email rather than traditional application email.

Its capabilities include:

Programmatic inbox creation
Sending and receiving email
Search
Threaded conversations
Webhooks
WebSockets
IMAP and SMTP support
Custom domains
Multi-tenant inbox infrastructure

The provider is therefore a strong fit when an autonomous agent needs its own identity and mailbox.

Best use cases for AgentMail
AgentMail works well for:

Autonomous assistants
Recruiting agents
Sales agents
Customer support agents
AI employees
Multi-agent systems
Applications where every agent needs an email identity

3. Nylas
Best for: AI agents that need access to existing user inboxes

Not every AI agent needs its own mailbox.

Sometimes an agent needs to operate inside a user’s existing Gmail, Outlook, Microsoft 365, Exchange, or IMAP account.

That’s where Nylas fits.

Nylas provides APIs for connecting applications to existing communication accounts and supports email, calendar, contacts, and scheduling workflows.

For example, consider an AI executive assistant.

The assistant may need to:

Read a user’s emails
Draft responses
Schedule meetings
Check calendar availability
Search previous conversations
Coordinate with other people

Creating a completely separate agent mailbox wouldn’t necessarily solve that problem.

Instead, the agent needs controlled access to the user’s existing inbox.

Why choose Nylas?

Nylas provides a unified API across multiple providers.

That can save development teams from building separate Gmail, Outlook, Microsoft 365, and Exchange integrations.

Best use cases for Nylas

Nylas is a good fit for:

AI executive assistants
Scheduling agents
Productivity applications
CRM automation
Recruiting platforms
Email assistants
Applications acting on behalf of users

4. Mailgun
Best for: Developers who need flexible inbound and outbound email infrastructure

Mailgun is a mature programmable email platform that supports both sending and receiving email.

For AI applications, its inbound email capabilities can be particularly useful.

An incoming email can be routed to an application, parsed, and then passed into an AI workflow.

For example:

Customer email → Mailgun → webhook → AI agent → business logic → response

This architecture gives developers the flexibility to build their own agent layer.

Why choose Mailgun?

Mailgun provides:

Email sending
Inbound email
Email routing
Email parsing
Webhooks
API access
Developer-focused infrastructure

It is therefore useful when developers want control over the email primitives while building their own AI-agent architecture.

Best use cases for Mailgun

Mailgun works well for:

Custom AI email workflows
Support automation
Email classification
Document processing
AI-generated notifications
Applications requiring inbound email

5. Resend
Best for: Modern applications that primarily need outbound AI-generated email

Resend has become popular among modern application developers because of its straightforward developer experience and strong integration with JavaScript and TypeScript ecosystems.

For AI applications, Resend can be a good choice when email is primarily an outbound communication channel.

For example, an AI application might generate:

Reports
Summaries
Notifications
Alerts
Account emails
AI-generated recommendations
Onboarding messages

In these cases, you may not need a dedicated agent inbox.

Why choose Resend?

Resend is particularly attractive for developers who want to get outbound application email working quickly.

It also integrates with React Email, which can be useful for applications generating polished transactional email templates.

Best use cases for Resend

Resend works well for:

AI SaaS applications
AI-generated reports
Notifications
Transactional email
Product updates
Developer-focused applications

How to Check if an Email is Disposable (Free Temp Email Checker)

Farhan Shaikh — Mon, 12 Oct 2026 09:42:49 +0000

Every day, millions of users sign up for websites using temporary email addresses. While these emails help protect privacy, they can also create problems for businesses.

If you run a SaaS product, e-commerce store, newsletter, or online community, disposable email addresses can lead to fake accounts, spam, coupon abuse, and inaccurate analytics.

In this guide, you’ll learn what disposable emails are, why they matter, and how you can quickly check if an email is disposable.

What Is a Disposable Email?
A disposable email (also called a temporary email or temp mail) is an email address that exists for a short time. Users create these addresses to receive emails without using their personal inbox. Most disposable email services delete emails automatically after a few minutes or hours.

People commonly use disposable emails to:

Protect their personal email address
Avoid spam and promotional emails
Test applications
Access free downloads without sharing their main inbox

While these are valid use cases, disposable emails can also be misused to create fake accounts.

Why Businesses Should Check Disposable Emails
Not every temporary email is harmful, but many businesses choose to detect them to improve data quality and prevent abuse.

Here are the most common reasons.

Prevent Fake Registrations
Users can create multiple accounts using different temporary email addresses. This inflates your user numbers without adding real customers.
Stop Free Trial Abuse
If your product offers a free trial, users can repeatedly sign up with disposable emails to avoid paying for your service.
Reduce Coupon Abuse
Many online stores offer discounts for new customers. Disposable emails make it easy to claim the same offer multiple times.
Improve Email Deliverability
Marketing emails sent to temporary inboxes often bounce or are never opened, affecting your sender reputation.
Keep Analytics Clean
Fake accounts can distort important metrics such as:

Active users
Conversion rate
Customer retention
Marketing performance
Accurate data leads to better business decisions.

How to Check if an Email Is Disposable
There are several ways to identify temporary email addresses.

Method 1: Use a Free Disposable Email Checker (Recommended):

The easiest and fastest method is to use an online disposable email checker.

Simply enter an email address, and the tool checks whether the domain belongs to a known temporary email provider.

If you’re looking for a free solution, try the Reloop Temp Email Checker:

👉 Reloop Temp Email Checker

It instantly tells you whether an email address is disposable, making it easy to detect fake signups before they enter your system.

Example:

john@gmail.com ✅ Personal email
user@mailinator.com ❌ Disposable email
demo@tempmail.com ❌ Disposable email

Method 2: Check the Email Domain:

Many temporary email services use publicly known domains.

Examples include:

mailinator.com
guerrillamail.com
yopmail.com
10minutemail.com
tempmail.com

If an email belongs to one of these domains, it is likely disposable.

However, this method requires maintaining an updated list because new temporary email providers appear regularly.

Method 3: Detect Disposable Emails Programmatically (API / Code):

If your website accepts user registrations, checking every email manually isn’t practical.

Instead, integrate disposable email detection into your signup process to automatically flag temporary email addresses before accounts are created.

This saves time and helps prevent abuse from the start.

cURL

curl -X POST https://reloop.sh/api/tools/v1/check \
  -H "Content-Type: application/json" \
  -d '{"email": "you@mailinator.com"}'

JavaScript

const res = await fetch(
  "https://reloop.sh/api/tools/v1/check",
  {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ email: "you@mailinator.com" }),
  },
);

const result = await res.json();

Python

# pip install requests
import requests

result = requests.post(
    "https://reloop.sh/api/tools/v1/check",
    json={"email": "you@mailinator.com"},
).json()

Response

{
  "input": "you@mailinator.com",
  "kind": "email",
  "domain": "mailinator.com",
  "verdict": "disposable",
  "isValidSyntax": true,
  "isDisposable": true,
  "disposableMatch": {
    "kind": "exact",
    "domain": "mailinator.com"
  },
  "isAllowlisted": false,
  "isRoleAddress": false,
  "isFreeProvider": false,
  "signals": {
    "syntax": "pass",
    "disposable": "fail",
    "role": "pass",
    "freeProvider": "pass"
  }
}

Why We Built the Reloop Temp Email Checker
At Reloop, we build simple and useful developer tools that solve real-world problems.

Our Temp Email Checker was created to help developers, SaaS founders, and businesses quickly identify disposable email addresses without maintaining large domain lists.

Whether you’re validating a single email or checking addresses before user registration, the tool provides instant results.

You can try it here:
👉 Reloop Temp Email Checker

You can also explore more free developer tools on our website:
👉 Reloop

When Should You Block Disposable Emails?
Blocking temporary emails isn’t always necessary.

Consider Blocking Them If:

You offer free trials
You run a paid SaaS product
You provide welcome discounts
You want high-quality customer data
You need verified users

Consider Allowing Them If:

Privacy is important for your audience
Users submit anonymous feedback
Registration isn’t required
Your service is completely free

Choose the approach that best matches your product and users.

Best Practices for Email Validation
Checking for disposable emails works best when combined with other validation methods.

We recommend:

Validate email format.
Detect disposable email domains.
Verify ownership with email confirmation.
Add CAPTCHA to signup forms.
Monitor suspicious signup activity.
Limit repeated registrations from the same IP address.

Using multiple layers of protection significantly reduces fake registrations.

Frequently Asked Questions

Are Disposable Emails Legal?
Yes. Temporary email services are legal and are widely used to protect personal privacy.

Can Disposable Emails Receive Verification Emails?
Yes. Most temporary email providers can receive verification emails immediately after the address is created.

Should Every Website Block Disposable Emails?
Not necessarily.

Some websites benefit from anonymous access, while others require verified users. The decision depends on your business goals.

Can Disposable Email Lists Become Outdated?
Yes. New temporary email domains are created frequently, which is why regularly updated detection tools are much more reliable than static blocklists.

Final Thoughts
Disposable email addresses are useful for protecting user privacy, but they can also be used to create fake accounts, abuse free trials, and reduce the quality of your customer data.

By checking email addresses during registration, you can improve security, keep your database clean, and make better business decisions.

If you need a quick and free way to verify an email address, try the Reloop Temp Email Checker:

Free Temp Email Checker: Disposable Email Detector | Reloop

Free temp email checker. Detect disposable inboxes, role addresses, and MX records. No signup, no SMTP probing.

reloop.sh

Looking for more developer tools?
Visit Reloop:

Reloop: Open-Source Email API & Infrastructure for Developers

Open-source email infrastructure for developers: transactional email API, SMTP relay, campaigns, webhooks, and agent inboxes. Reloop Cloud or self-hosted.

reloop.sh