Email not sending

This guide explains how to find out why a Business Email message stays in the outbox or shows a sending error, and how to fix the most common causes.

Before you begin

The outgoing settings for your app: server mail.apncloud.com, with port 465 and SSL/TLS, or port 587 and STARTTLS. See IMAP and SMTP settings.
The exact error message, if one is shown.
Access to webmail to test your password.

Check the outgoing server. It should be mail.apncloud.com.
Check the port and security. Use port 465 with SSL/TLS, or port 587 with STARTTLS. Do not mix them.
Test your password in webmail. Sign in to webmail with the same password. If webmail works and the app does not, the problem is in the app settings.
Try the other port. If port 465 fails, try port 587 with STARTTLS, and the other way round. Keep the security setting that matches the port.
Note the exact error text before you contact support.

Never turn off encryption

Do not switch security off to make sending work. Keep SSL/TLS or STARTTLS on, and check the server name instead.

The message leaves the outbox and arrives at its recipient.

Some networks block mail ports. Try a different network, such as mobile data, to check. If mail sends on one network but not another, contact your network administrator.
A recipient rejected the message. Check the recipient address for spelling mistakes. If many messages are rejected, read Email authentication errors.
The problem continues. Open a request in the Client Area with your email address, the app you use, the server and port, and the exact error text. Never include your password.

2026-10-27