I have a custom list on Sharepoint 2010 that has a SPD workflow attached that sends out an email to 2 Exchange distribution groups, and a small handful of individuals. This has been working fine for a long time (daily for about a year), but recently the emails have stopped working correctly.
The individuals receive the email fine, but when looking at the "To" field in outlook, the groups names are unresolved and displaying in DOMAIN\GROUP NAME format. Nobody in either groups are receiving the email.
What could be causing this problem?