ERROR: 354 Enter mail, end with "." on a line by itself.
Fro time to time we get the following error:
[2016-06-01 12:47:31] Cli 31839/2: Submitted message ': <161348943.91464799723129.JavaMail.email@example.com>' to unix.in.
response: '354 Enter mail, end with "." on a line by itself.'
It happens randomly when somebody tries to send mail with several attachments.
Affected subsystems: webmail, imap
The error in webmail says that mail wasn't sent properly, but send it after some time automatially. (see first screenshot)
The receipient see only part of message - usually broken an without attachments which drops to junk folder. (see second screeenshot)