- Plesk for Linux
- Plesk for Windows
Unable to set up a mail account on an external mail client (e.g. Outlook) when the domain name is using Cloudflare proxy:
CONFIG_TEXT: Connection could not be established with host example.com
Unable to connect to example.com:587
The webmail firstname.lastname@example.org works correctly.
Cloudflare does not proxy the mail traffic, it can only proxy traffic going over the HTTP/HTTPS ports in a specific range: https://support.cloudflare.com/hc/en-us/articles/200169156
Mail client tries to fetch the real Plesk IP address using a domain name to set up a connection but fails because the request ends up on the Cloudflare side and the wrong IP is obtained.
There are 3 solutions available:
- Configure mail client using Plesk mail server IP address.
- Configure mail client using a hostname that resolves directly to Plesk mail server IP address.
- Disable Cloudflare for the affected domain.