Hi,
all of a sudden our JIRA Service Desk sends up to 10 notification mails for the same case. So when one of our agents adds a comment to an issue, JIRA sends the notification mail 10 times.
This behaviour is new to use, I´ve made no changes to the configuration.
Has anyone ever seen such a misbehaviour?
EDIT: I´ve been looking into atlassian-jira-outgoing-mail.log to find out that there are plenty of these messages:
com.atlassian.mail.MailException: javax.mail.MessagingException: Exception reading response;
nested exception is:
java.net.SocketTimeoutException: Read timed out
This is mailbox independent 
Regards
Simon