Resolution
Typical symptoms:
In the content of a mailing, a member's email address is merged instead of the member's first name for the merge tag %%firstname%%.
Resolution:
If the member record does not have a value for the FullName_ column, then the value for the EmailAddr_ column is used instead. If the member has a value in the FullName_ column, the name up to the first space is taken as the first name.
Note: If the system has a user defined demographic field named firstname, use the merge tag %%merge members_.firstname%%.