We have strange issue, since started using Exchange 2007 SP1, I'm using Thunderbird as IMAP4 client, charset="iso-8859-1", now in Estonian language we have umlauts (iso-8859-1 does include them), or so called national characters (), when I'm writing new message, all umlauts are visible and when I sent the message, the receiver also sees the umlauts, but in Sent Items folder where the message is stored, all umlauts are gone and replaced with question mark. And nor always, for example, I'll do Reply to all, 2 receivers, one is using charset="iso-8859-1" and second charset="windows-1252". Now when to: using is charset="iso-8859-1 user and cc: is using charset="windows-1252" umlauts are gone and replaced with question mark in saved message in Sent Items. But when to: is using charset="windows-1252" user and cc: is using charset="iso-8859-1" umlauts are ok in saved message in Sent Items. Even more strange is that when I'm sending new email to user who is using some other charset, than I am. Then also all umlauts are gone in saved message in Sent Items, however I can see from that message headers, that messages charset is ok - charset="iso-8859-1" And when I'm include some image, doc,. etc, all umlauts are always ok in saved message in Sent Items. So whats wrong? In Exchange 2007 default properties are set like described in http://technet.microsoft.com/en-us/library/aa996309(EXCHG.80).aspx: Exchange rich-text format - Determined by individual user settings Character Sets - Mime character and Non-MIME character set - Western European (ISO). What else can we do? Should change the TNEFEnabled parameter to $true? I found some doc about Exchange 2003 - How to set encoding for POP3 and IMAP4 for specific users - http://support.microsoft.com/kb/836588 but this does not help with Exchange 2007. Does Exchange 2007 have some similar settings? BTW, using open source MTA/IMAP (postfix/dovecot) and same IMAP client software and same receivers, the umlauts are always ok. Any help is welcome.