Messages being deleted automatically from 'Deleted' folder

[AlanJH]

I retained deleted mails in my Deleted or Deleted Messages folders for several months after deletion in case of later disputes with correspondents. However I now find that they have vanished from these folders after a couple of weeks. I generally view mails either using Thunderbird on a laptop or Mail on an iPad. Mail has no obvious options but Thunderbird is set to 'Don't delete any messages'

Any suggestions please?

[AlanJH]

(In BT Mail settings, "Empty trash on logout" is NOT ticked)

[licquorice]

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@AlanJH wrote:

I retained deleted mails in my Deleted or Deleted Messages folders for several months after deletion in case of later disputes with correspondents. However I now find that they have vanished from these folders after a couple of weeks. I generally view mails either using Thunderbird on a laptop or Mail on an iPad. Mail has no obvious options but Thunderbird is set to 'Don't delete any messages'

Any suggestions please?

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Yes, create a 'Pending' folder.

[gg30340 · Accepted solution]

The trash folder empties on a 30 day rolling program.

The reason that your email apps trash folder contents are also deleted despite you ticking the "Do not delete" box is because your email account on T'bird and your iPad will have been set up as an IMAP account and this replicates what takes place on the BT server. ie the trash is cleared/deleted on the BT servers therefore it show as being deleted on your other devices.

If you don't want things deleted don't put them in trash. As has already been suggested set up a "Pending" folder until such time that you have made up your mind that you no longer want it. 

Other companies such as Gmail also do this.

Delete or recover deleted Gmail messages - Computer - Gmail Help (google.com)