iPhone Deleting mail message in one account also deletes in a different account

[macuser_123]

I recently updated my iPhone 7 from iOS 12 to iOS 13.3. Today I started noticing an odd behavior in Mail. I am fairly certain it was not happening in iOS 12, but not sure if started happening immediately after upgrading to 13.3 or a little later.

The way I have my email set up, most mail is delivered to my iCloud address, which is then forwarded to a different email account "X", but set to not be deleted from iCloud. I handle my mail using account "X", and use iCloud as sort of an archive, so that if I delete anything from account "X" and want to go back to find it, I can search my iCloud mail. I have my iPhone set up to view mail both from iCloud and also account "X".

Today I noticed that after deleting some messages from account "X", I went back to my iCloud account and they were missing from there as well. I did some testing, and it seems whenever I read a message from account "X", the corresponding message is also marked as read from the iCloud account even if I never explicitly opened the message in the iCloud account. And when I delete a message from account "X" is also gets removed from the iCloud account. It doesn't happen with every message, but definitely with many of them as I started paying attention. When I look in the All Trash folder, only one of the two messages that gets removed shows up there. It's as if Mail is linking them and treating them as one message and whatever happens to one happens to the other.

I thought maybe it had something to do with message threading, but I do not organize by threads and checked my settings to confirm that. Anyone know what is going on? Obviously having messages unwantedly deleted is troubling behavior. I apologize if this overlaps with an existing thread; after searching and reading through messages describing (many many many...sigh) problems in iOS Mail, I don't think I saw any that described this particular problem exactly.

Thanks.

 

[jpn]

I recently updated my iPhone 7 from iOS 12 to iOS 13.3. Today I started noticing an odd behavior in Mail. I am fairly certain it was not happening in iOS 12, but not sure if started happening immediately after upgrading to 13.3 or a little later.

The way I have my email set up, most mail is delivered to my iCloud address, which is then forwarded to a different email account "X", but set to not be deleted from iCloud. I handle my mail using account "X", and use iCloud as sort of an archive, so that if I delete anything from account "X" and want to go back to find it, I can search my iCloud mail. I have my iPhone set up to view mail both from iCloud and also account "X".

Today I noticed that after deleting some messages from account "X", I went back to my iCloud account and they were missing from there as well. I did some testing, and it seems whenever I read a message from account "X", the corresponding message is also marked as read from the iCloud account even if I never explicitly opened the message in the iCloud account. And when I delete a message from account "X" is also gets removed from the iCloud account. It doesn't happen with every message, but definitely with many of them as I started paying attention. When I look in the All Trash folder, only one of the two messages that gets removed shows up there. It's as if Mail is linking them and treating them as one message and whatever happens to one happens to the other.

I thought maybe it had something to do with message threading, but I do not organize by threads and checked my settings to confirm that. Anyone know what is going on? Obviously having messages unwantedly deleted is troubling behavior. I apologize if this overlaps with an existing thread; after searching and reading through messages describing (many many many...sigh) problems in iOS Mail, I don't think I saw any that described this particular problem exactly.

Thanks.

i think you are right in that Mail has it linked somehow.

iCloud is of course IMAP, meaning that mail should always remain on the server, even after being opened/read, or moved to different mailbox/folder that is also on the server.
first thing to check is in your iCloud/Mail/Advanced settings (where you can check/change exactly where you are telling iCloud mail to be stored (meaning: on the server, or, on yr phone (locally).

then, regarding moving iCloud email to Account X, do you have any rule set (like in iCloud.com) that is telling incoming iCloud mail to be copied to Account X? (you don't mention how you have been before accomplishing that move to Account X) but a simple move of the mail will in fact result in a normal behavior of deleting it from the iCloud server.

 

[macuser_123]

Hi-- thanks for your reply.
Via the iCloud.com web interface, I have mail forwarding set on (iCloud Mail->Settings->General->Forwarding->"Forward my email to "Account X"; Delete messages after forwarding is UNselected)

I can verify that up until the moment that the message gets deleted it remains in my inbox on the iCloud server because my Mac which is also set up to access iCloud can also see it, and also I can see it on the iCloud.com inbox. The moment I delete the message from Account X, it disappears from the iCloud mailbox on my phone, Mac and iCloud.com and shows up in the iCloud trash folder.

I don't know if this some new feature where iOS 13 Mail is trying to be overeagerly helpful by figuring if I delete the message from one account, I must (wrongly) want "identical" messages deleted from all accounts, or this is rather a bug.

 

[jpn]

Hi-- thanks for your reply.
Via the iCloud.com web interface, I have mail forwarding set on (iCloud Mail->Settings->General->Forwarding->"Forward my email to "Account X"; Delete messages after forwarding is UNselected)

I can verify that up until the moment that the message gets deleted it remains in my inbox on the iCloud server because my Mac which is also set up to access iCloud can also see it, and also I can see it on the iCloud.com inbox. The moment I delete the message from Account X, it disappears from the iCloud mailbox on my phone, Mac and iCloyud.com and shows up in the iCloud trash folder.

I don't know if this some new feature where iOS 13 Mail is trying to be overeagerly helpful by figuring if I delete the message from one account, I must (wrongly) want "identical" messages deleted from all accounts, or this is rather a bug.

hi
on iCloud.com i don't see a setting that would allow or prevent delete messages after forwarding.
on my iCloud.com there are two options that involve transferring email: one is to transfer. the other one is to mark a message as read after transferring it.
where are you unselecting a setting that otherwise if not checked "delete messages after forwarding".

 

[macuser_123]

Hi-- this is the settings window that I am looking at.

 

[BrianBaughn]

I have seen this sort of behavior in past years in my Mac's Mail app as well as iOS. Duplicate messages in different accounts have been somehow, sometimes linked and actions performed on the emails affect the other copies.

I suspect the info in the email headers "matches" in some qualifying way and the email client app sees it as a single email.

I suppose one way to backup the emails safely would be yet another forwarding email account in between the two existing ones and NOT active in your iOS Mail client. You could set up a third-party email app to access the new account.

Another way would be to turn off mail on the iOS device for your iCloud account and access it via a third-party account when you need to.

 

[NoBoMac]

I suspect the info in the email headers "matches" in some qualifying way and the email client app sees it as a single email.

This.

Believe every email has a "Message-ID" field in it. A unique ID generated for each message sent.

And as mentioned, iOS Mail might be indexing the emails off that. iOS is most likely doing similar/code-sharing as MacOS. On Mac, under the ~/Library/Mail/V7/MailData folder is an SQLite database (Envelope Index) that tracks lots of the mail information ("metadata", Subject, where on disk, etc), and could very well be the database is using Message-ID as a key index. Delete the record, delete all of it.