Server replied: 111 Can't open SMTP stream.
You've either configured SquirrelMail badly and specified an SMTP server which doesn't exist, or the SMTP server is down.
- Either run SquirrelMail-configuration again and specify an SMTP server that exists (option 2 on the main menu)
- Edit the SquirrelMail config.php file, on linux this would be, from the terminal, sudo nano /etc/squirrelmail/config.php
SMTP Server down
- Restart the SMTP server- with postfix this would be sudo postfix stop and sudo postfix start