The docstring for Mail.add_header states that the headers can be a Header object or a dict, however, passing a dict breaks due to attempted if header.personalization is not None: check.
Checklist
[x] I acknowledge that all my contributions will be made under the project's license
[x] I have made a material change to the repo (functionality, testing, spelling, grammar)
Fixes
The docstring for
Mail.add_header
states that the headers can be aHeader
object or adict
, however, passing adict
breaks due to attemptedif header.personalization is not None:
check.Checklist
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