Troubleshooting

Why does my SMTP connection time out?

Fix SMTP connections to smtp.emailit.com that hang or time out, usually because your network or cloud provider blocks port 25.

Updated Oct 1, 2026

Use this article when your application can’t open a connection to the Emailit SMTP relay at all. If the connection opens but you get an error code, see SMTP troubleshooting instead.

Symptoms

Your mail library reports ETIMEDOUT, Connection timed out, Connection refused or Could not connect to SMTP host.
The client hangs for 30 seconds or more before failing, and nothing appears in Email APILogs.
The same settings work from your laptop but fail from a server, container or serverless function.

Cause

The connection is blocked before it reaches Emailit. Common reasons:

Port 25 is blocked. Many hosting and cloud providers (for example AWS, Google Cloud, Azure and DigitalOcean) block or throttle outbound port 25 by default to fight spam. Residential ISPs often do the same.
Other submission ports are blocked too. Some providers also block 465 and 587 on new accounts.
An egress firewall or security group only allows specific destination ports.
The host name is wrong. The relay is smtp.emailit.com.

Emailit listens on these ports:

Port	Encryption	When to use
587	STARTTLS	Recommended default
465	Implicit TLS	When your client prefers TLS from the first byte
2525	STARTTLS	When 25 and 587 are blocked
2587	STARTTLS	When 25 and 587 are blocked
25	STARTTLS	Only if nothing else is available

Fix

Switch to port 587. Set the host to smtp.emailit.com, the port to 587 and enable STARTTLS. Port 25 is rarely the right choice for an application.
Test the port from the machine that sends. Run the check on the server itself, not on your laptop.
Terminal
```
nc -vz smtp.emailit.com 587
nc -vz smtp.emailit.com 2525
```
On Windows, use Test-NetConnection smtp.emailit.com -Port 2525 in PowerShell. A working port reports a successful connection (TcpTestSucceeded : True in PowerShell). A blocked port times out.
Use 2525 or 2587 if 587 is blocked. Both offer STARTTLS and are rarely filtered. Keep your client’s STARTTLS setting on.
Open the port in your firewall. Allow outbound TCP to smtp.emailit.com on the port you chose, in your security group, network ACL or container network policy.
Ask your provider to unblock port 25 only if you must use it. Most providers have a request form. Moving to 587 or 2525 is faster.
Consider the HTTP API. If your platform blocks SMTP entirely, send through the Email API over HTTPS on port 443. See API or SMTP?.

Once the connection works, every message you submit appears under Email APILogs with the source SMTP. If the connection now opens but the handshake fails, see Why do I get TLS errors when connecting to SMTP?. For every setting in one place, see SMTP settings.

Still stuck?

Contact support or ask in Discord. Include the port you tried, where your app runs (provider and region) and the output of the nc or Test-NetConnection check.