File > Export > Export messages as .EML disambiguates thus:
2006-12-11 01-03-00 Another spam forwarded by ToSpamtrap (1).eml
message list > Save As… disambiguated thus:
2006-12-11 01-03-00 Another spam forwarded by ToSpamtrap_1.eml
This inconsistency needlessly annoys downstream tools.
Please make the two use the same scheme.
Thanks.