- They do not have a FAQ or support page on BIMI posted today, but they do fully support BIMI on both Fastmail and Pobox.
- Fastmail will show BIMI indicators in place of avatars for those domains who have the proper DMARC record setting, valid BIMI records, and a valid SVG image specified.
- The SVG image file must validate to the svg-tiny-ps profile.
- If a Verified Mark Certificate (VMC) is present, they will validate it, but they do not currently require it.
- If a BIMI selector header is present, they will use it, but they have yet to notice this in use. (Which suggests to me that you don't have to worry about this today.)
Fastmail now supports BIMI
Pobox and Topicbox) Fastmail now supports BIMI. Fastmail's Marc Bradshaw was kind enough to confirm for me: