Matthew Ogilvie wrote patches to make Fetchmail 6 support xoauth2 which is compatible with OAuth2 and OAuthBearer.
I have updated these patches for recent releases:
| fetchmail version | date | file size | md5sum | sha256sum |
|---|---|---|---|---|
| 6.4.27 (patch also works on some earlier releases) | Aug 10, 2021 | 18491 bytes | 4e7648d3364878936977e74d4551ea58 | e09771737bb588bd7918cdeb3166072c7679fe2002597ccfb79beabb7ca77837 |
| 6.5.0.beta7 | Mar 1, 2022 | 18394 bytes | 56ca24974abb653345bfaf79b8440357 | 98e0572ee50c6122338bf861911c526e484b85916a884dc4a5b61ff787dd109b |