Knowledge Base

Unable to receive emails on Plesk with Mail Enable

Symptoms

Mail is sent, but not received on Windows server with MailEnable.

The following error can be found in the POP3 logs in MailEnable > Servers > localhost > Services and Connectors > POP > Logs > Activity:

ME-F0090: Unable to bind to IP Address (203.0.113.2), Port (110), Error (10048). Could not start service. Check that another service is not running or security software has not prevented access to the port.

It is not possible to connect to Outlook:

PLESK_INFO: Log onto incoming mail server (POP3): The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP). The server responded: -ERR Can not connect to e-mail server. Error:100502
Port 25 is shown as filtered for inbound connections, as well as 995, 110 and all other mail-related ports, but firewall is disabled on the server:

# nmap 203.0.113.2 -p 25
Host is up (0.21s latency).
PORT STATE SERVICE
25/tcp filtered submission
Nmap done: 1 IP address (1 host up) scanned in 2.41 seconds
Telnet from outside is not possible:

# telnet 203.0.113.2 25
Trying 203.0.113.2 …
telnet: Unable to connect to remote host: Connection timed out
On the server telnet to any IPv4 IP address is not possible:

C:> telnet 203.0.113.2 25
Could not open connection to the host, on port 25: Connect failed

Cause

MailEnable misconfiguration.

Resolution

Connect to the server via RDP.
Go to Start > MailEnable > Right-click on SMTP > Properties > Inbound.
Set Only bind to these selected IP addresses option and select all the IPs.
Repeat previous steps for IMAP and POP services in MailEnable.
Restart the affected services after applying the changes at Start > Services > restart Mailenable SMTP Service/Mailenable IMAP Service/MailEnable POP Service.