This does not happen on every email but is starting to affect all clients - started about 2 months ago and is getting worse random font changes . text will be in Arial and then switch to other fonts like times roman - Changes color sometimes missing email content . email content that was typed into the message is randomly removed (full lines of text) - sender receives a different message from what was sent. Very unacceptable source html displayed in-line with text . I have upgraded(migrated) from SBS2003 to SBS2011 Standard - via MS migration plan I have removed the AVG antivirus clients and replaced with MSE 2.0(and have sent email with no antivirus) I have replaced signature files I have loaded all windows updates on clients and SBS2011/Exchange 2011 Email looks fine in Sent Items - but when received it has changed BOTH Internal and external email (internal to the exchange server - external thur Smarthost SMTP) Any Ideas on why this is happening? As you know Email is VERY important and must arrive correctly

Look at that smart host. Also look at your firewall and make sure it isn't doing any SMTP favors for you, like "cleaning up" SMTP sessions.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi Dano, I also suggest you follow these steps to have a try: 1. Make sure you didn’t have any transport agent. 2. Use OWA to send email internal (from an internal user to another internal user) and check the email in OWA. Thanks, Evan Liu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Not sure how to check my firewall for SMTP Cleaning Up? I am not sure what you mean here - how do I not use a transport agent? Thank for your efforts! Dano

Hi Dano, Since this issue also may be caused by transport agent, test without transport agent can help us clarify whether the problem is on Exchange Server or on transport agent. If you don’t have any transport agent installed before, just to test in OWA and paste the result in your next post. You can know more about transport agent from these documents: Understanding Transport Agents http://technet.microsoft.com/en-us/library/bb125012.aspx Uninstall a Transport Agent http://technet.microsoft.com/en-us/library/bb125265.aspx Thanks, Evan Liu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

I think I have narrowed this issue down a little... We have 2 Authorative Domains in use - companyA.ca & companyB.com Our 2 MX records point to our SBS2011 server - thru our router/firewall email received to our server works great - both domains into end user exchange mailbox If domain 'A' email address is set as primary when outlook 2007/2010 connects to server then Exchange sends email OK. When using POP3 account (not to receive) to send email from Domain 'B' the email 'sometimes' arrives with errors (as described above) I can reproduce this error. Both domains use the same SMTP server (external ISP) If I change around domain A for domain B on exchange/outlook - same issue - domain 'A' will have some errors after sending email. We have migrated to SBS2011 from SBS2003 recently because this was also happening with SBS2003... I am thinking Outlook is the issue boyh Outlook 2007 and 2010 - maybe... We do NOT have a test server (small shop) and I do not want to remove Agents in a production server unless absolutly necessary. Thank for your Efforts with this issue! Dano

POP3 is not used for sending mail, just for retrieving mail. Your POP3 clients use SMTP to send mail. See how the ones who send mail are configured to send mail. Consider eliminating the use of POP3. It's really a very old and feature-poor protocol. If your users are on Outlook, use MAPI, otherwise, consider IMAP.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi Dano, Do you follow my suggestion to test in OWA? If not, please test it and paste the result in your next post. Thanks, Evan Liu TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.