What an email keeps
An email with a login in it stays in the sender’s Sent folder and in every recipient’s inbox, on every device where that mail is synced, until someone deletes it. When it is forwarded, or answered with the earlier mail quoted below, the password goes along. When the password changes, the old one stays in those mails and a new mail goes out.
Whoever gets into one of those mailboxes can search it for the word “password”.
You decide who can open it
Access is set per shared vault. The office vault can go to the people in the office and a client’s vault to the people who work with that client. When someone should no longer have a password, you take away their access in one place instead of hoping they delete a mail.
Removing access stops new downloads. It does not undo what someone already saw or copied, so change a password that a person who leaves knew. When someone leaves the team goes through that step.
Change it once
When the password changes, change it in the vault. Everyone with access sees the new one there, and the old one is not left behind in old mails.
In short
- An email keeps a password in every mailbox it reached, and in forwards and replies
- A shared vault keeps it with the people you give access
- Access is set per shared vault and removed in one place
- Change the password once, in the vault