Lost access to a mailbox but still receiving mail

karlito96

Hello all,

I have a few mailboxes running on mailcow. I am using my iphone as a client for all of them but one in particular is not updating.

When I try to refresh and check for new mail from my iphone I get the following error in the dovecot log:
imap(karlito@XXX)<945><G2h/6dj1w9RWsZQf>: Error: Mailbox INBOX: UID=690: read() failed: read(/var/vmail/XXX/karlito/Maildir/cur/1677030501.M849176P15478.63ee728bab29,S=34003,W=34891:2,Sb) failed: Decryption error: no private key available (read reason=12/12 headers not cached (first=BCC) (Mail has other cached fields, reset_id=1677030425))

Things get even weirder - one of the mailboxes the does work, if I try to set it up with Thunderbird, the server and username are discovered, however when I try to fetch the mail I get the same error as above, even tho this particular mailbox is working on my iphone:
imap(poshta@XXX)<1060><Fm5+9Nj1wshWsZQf>: Error: Mailbox INBOX: UID=1: read() failed: read(/var/vmail/XXX/poshta/Maildir/cur/1677030121.M387659P15285.63ee728bab29,S=9970,W=10111:2,S) failed: Decryption error: no private key available (read reason=4/14 headers not cached (first=NEWSGROUPS) (Mail has other cached fields, reset_id=1677030122))

Does anybody know what the issue may be?
I am really lost and need my mail to work..

Thanks!

karlito96

From within the container I have verified both paths referenced, do exist:
root@100fbafb95d1:/# ls -l /var/vmail/XXX/karlito/Maildir/cur/1677030501.M849176P15478.63ee728bab29\,S\=34003\,W\=34891\:2\,Sb -rw------- 1 vmail vmail 13350 Feb 13 2022 '/var/vmail/XXX/karlito/Maildir/cur/1677030501.M849176P15478.63ee728bab29,S=34003,W=34891:2,Sb' root@100fbafb95d1:/# ls -l /var/vmail/XXX/poshta/Maildir/cur/1677030121.M387659P15285.63ee728bab29,S=9970,W=10111:2,S -rw------- 1 vmail vmail 5714 Aug 4 2021 '/var/vmail/XXX/poshta/Maildir/cur/1677030121.M387659P15285.63ee728bab29,S=9970,W=10111:2,S' root@100fbafb95d1:/#

karlito96

Furthermore my keys also exist (and are getting backed up daily):
[root@i-09537060f414da791 ~]# ls -l /var/lib/docker/volumes/mailcowdockerized_crypt-vol-1/_data/*pem -rw------- 1 401 root 241 Feb 23 17:15 /var/lib/docker/volumes/mailcowdockerized_crypt-vol-1/_data/ecprivkey.pem -rw-r--r-- 1 401 root 178 Feb 23 17:15 /var/lib/docker/volumes/mailcowdockerized_crypt-vol-1/_data/ecpubkey.pem [root@i-09537060f414da791 ~]#
Any help will be greatly appreciated..

karlito96

This seems to be an issue the mailcow community is not very keen on providing support for or is simply somewhat of uncharted territory.

I found numerous discussions online from the past 2 years similar to my problem and no clear resolution seems to exist.

Here are some of the other discussions:
mailcow/mailcow-dockerized2395
https://community.mailcow.email/d/2236-mail-cant-be-readdecrypt-after-restore
https://community.mailcow.email/d/955-cant-restore-to-a-new-server
https://community.mailcow.email/d/364-imap-issues/5
https://community.mailcow.email/d/2082-certain-emails-no-longer-loading-corrupted/3

At this point there are 2 things I have to attempt with the hope of recovering my mail (2000+ messages).

1) Do a full backup of mailcow on existing host, restore it to a new temporary host, sync the restored mail from temp to existing host.
2) If 1) doesn’t work, will need to attempt the mailcow migration detailed in https://docs.mailcow.email/en/i_u_m/i_u_m_migration/ to a dummy server and then try to sync my mail from there.

Anyways this seems to be a brutal PITA and am heavily disappointed it hasn’t been documented properly in the mailcow docs considering the amount of people who encountered this issue over the past 2 years.

karlito96

Luckily I managed to recover my mail as the backups (which included crypt volume) were stored on NFS which get’s daily backups and the mailcow server has a cronjob to write a new backup daily.
I started attempting a restore of crypt from each of the backups and attempting which one will decrypt my email.
After all the mail was decrypted I restored the latest key I had in the crypt backup and encrypted all the mail with it.

Regardless still not sure how the issue occurred in the first place, I restored mailcow some days ago but the issue seems to have appeared afterwards and still a full restore which includes crypt should have restored the original keys.