Mails are not getting delivered from the server an got stuck in outbound queue with error:
Communications Error: Socket connection to alt4.gmail-smtp-in.l.google.com failed (error 10013). The host was either not contactable or it rejected your connection. Socket Family = 23; Host=1234:f8b0:400c:c03::1abcd; Port=25
It may be not possible to connect locally to SMTP port while service is running properly:
C:> telnet 127.0.0.1 25
Connecting To 127.0.0.1...Could not open connection to the host, on port 25: Connect failed
McAfee protection is installed.
Mcafee Antivirus may block mail delivery. From McAfee Antivirus log:
Blocked by port blocking rule C:\\Program Files (x86)\\Parallels\\Plesk\\Mail Servers\\Mail Enable\\Bin64\\MESMTPC.EXE Anti-virus Standard Protection:Prevent mass mailing worms from sending mail 126.96.36.199:25
Disable Access Protection in Mcafee, it can be done in McAfee:
- Double-click Access Protection.
- Deselect Enable Access Protection.
- Click OK.
Or remove it.