Problem: When using "Send as" with the email address of a distribution group, a mail contact or a linked mailbox as sender, the sent emails are not copied into the journal mailbox if Exchange standard journaling is used. Consequently, with journal archiving, these emails are missing from the archive as well. For mail contacts and linked mailboxes, this applies to received emails as well.

Solution: Create an Exchange journal rule that applies to the email address of the distribution group or mail contact. You can find more information in the respective Exchange implementation guide:

MailStore Help: Archiving Emails from Microsoft Exchange 2007 - Configuring Premium Journaling

MailStore Help: Archiving Emails from Microsoft Exchange 2010 - Configuring Premium Journaling

MailStore Help: Archiving Emails from Microsoft Exchange 2013 - Configuring Premium Journaling

MailStore Help: Archiving Emails from Microsoft Exchange 2016 - Configuring Premium Journaling

Background: When Exchange standard journaling is used, Exchange uses the Active Directory attribute homeMDB to look up the Exchange database where the mailbox of an email's sender or recipient resides. The database's AD attribute msExchMessageJournalRecipient contains the address of the journal mailbox.
Distribution groups and mail contacts do not have a mailbox of their own, therefore the homeMDB AD attribute is missing and standard journaling does not work here. This is the expected behavior.

More Information:

https://technet.microsoft.com/en-us/library/ff772433.aspx 

https://technet.microsoft.com/en-us/library/aa998649(v=exchg.150).aspx

Article-ID: KB20150815-0-EN (Deutsche Version)