You have to post relevant sections of your IMail logs and errors received by your clients. Most problems cannot (or should not) be solved by guesswork.
--Sandy
------------------------------------Sanford Whiteman, Chief TechnologistBroadleaf Systems, a division ofCypress Integrated Systems, Inc.
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The relevant lines are the 'Stack connect fail' lines, which indicate an issue with the DNS server used by IMail.
Try searching the mailing list archives (http://www.mail-archive.com/imail_forum@list.ipswitch.com) for 'stack connect fail' for a lot more info. http://www.mail-archive.com/imail_forum@list.ipswitch.com/msg60008.html is exemplary.