Fix/configure sender for email notification

Hi, after moving from travis-ci.org to travis-ci.com notifications have stopped working for the apache/httpd project.

The email notifications used to use an enveloper sender of “builds@travis-ci.org” but now use an (unpredictable?) Amazon SES address like 010f017dc5f84834-cb22bfa4-d102-44ae-bd3a-fe2668ab01b9-000000@us-east-2.amazonses.com - this is hard/impossible to whitelist safely when we are delivering to a mailing list.

Could either

a) the enveloper sender be changed to a fixed address, or
b) allow us to configure the enveloper sender in .travis.yml?

TIA, Joe Orton

Imprint