Email service on Squid 14 server is currently down. We are looking at the problem and will post updates here as information becomes available.
UPDATE: This is now fixed. What happened is that we had one issue left over from the recent Plesk update and to fix that issue we ran a tool that is supplied with Plesk. Unfortunately there are issues that were unknown to us with that tool and the version of Plesk we upgraded. This caused for mail to bounce and prevented people from logging into their email accounts.
The tool was used at 4:15 PM PST and the problem was fixed at 4:55 PM PST. So for that period of time any email sent to address would have bounced and you would not be able to log into the email account.