Hi @NatalieAtSafe,
From this Q&A;: SMTP error
The issue has been filed as C125117 (PR76958) and I was notified that it has been fixed in FME 2017.1 Beta already. I confirmed that the original issue has been resolved in FME 2017.1 Beta with Python 3.5, but the fixed Emailer newly causes this error when running with Python 2.7. I think the error apparently indicates that the implementation of the Emailer in FME 2017.1 Beta doesn't conform to Python 2.7 specifications.
Emailer: <type 'exceptions.TypeError'>: character mapping must return integer, None or unicode
Nearly two months have passed since I reported the error above, but it has not been resolved yet in the latest Beta build 17498.
Could you please check the current status of the PR?