Please note that the deadline for removing py2 versions is approaching fast.
Maybe put a block on Bug 694800.
I found out about this issue this morning. Seamonkey seems to depend on the old version, so it needs to be checked if seamonkey can use the newer version.
However, it seems Enigmail dropped support for Seamonkey in 2019: https://admin.hostpoint.ch/pipermail/enigmail-users_enigmail.net/2019-January/005280.html.
And for Thunderbird recently: https://www.enigmail.net/index.php/en/home/news/71-2021-08-31-end-of-support-for-thunderbird.
I've been actually thinking when to last-rite enigmail. It's not supported by thunderbird's in tree anymore, although the last versions should provide a tool to migrate your enigmail settings into thunderbirds >78 (if my memory servers me right).
You may want to check if the latest release of enigmail, 3.0.0 or something, supports seamonkey? Then we can bump enigmail, stabilize the latest version and keep using that with seamonkey. I believe everyone using Thunderbird have already migrated their PGP settings, so there's no need to keep the older versions of enigmail in tree anymore due to that.
^ (I obviously assumed the latest version of enigmail is python3+ ready, haven't checked that)
According to the Seamonkey 2.53.11 release notes:
The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
So, the lowest version in portage is already newer than that. However "unsupported" doesn't mean it doesn't work (some people seem to have been using it with newer versions).
Personally I haven't been using the email application of the seamonkey suit, so I don't know how it works in combination with enigmail. Let alone how to use/test the migration tool. According to the enigmail devs, only very few seamonkey users use enigmail (I thought I read a number of 0,5% of all enigmail users).
Maybe it's best to give the seamonkey crypt USE flag a warning message that people should migrate away and drop it completely in some later version.