I understand problem 1 and can assist, but I do not understand problem 2. Please provide more detail. The first problem seems to be focused on moving from a POP account TO a t-online accoount - but problem 2 seems focused on moving the sent folder FROM the t-online account.

Thanks David

Yes the first problem is my t-online account in Thunderbird which is a pop. Unfortnately the settings were wrong, so that the incoming Emails were deleted after 14 days from the t-online Server. They exist in the t-online account in Thunderbird, but not in my origianal t-online account at Telekom.

The second problem was a data transfer problem from my desktop to my new Laptop. Its correct. The send folder of my t-online account at Telekom was not transfered in my t- online account in Thunderbird. But the send emails still exist in the original t-online account at the Telekom server. So how can I transfer them to the t- online account in Thunderbird?

So what do you suggest to do?

Okay, to further clarify, thunderbird is an email client (agent), t-online is an email account, but what is telecom? You had a t-online account running on a telecom server? What server is the t-online account now running on? You seem to be equating thunderbird and telecom, but they are different entities.

Settings in Thunderbird

Servertyp: Pop Server: securepop.t-online.de

German Telekom ist my Email provider. Of course I know that Thunderbird is an Email client. But why is this relevant?

Settings in T-online

Posteingangs-Server: secureimap.t-online.de 993 SSL Postausgangs-Server: securesmtp.t-online.de 465 SSL POP3-Server: securepop.t-online.de 995 SSL / TLS POP3- / SMTP- / IMAP-Zugang Aktiviert

Can you help me?

Thanks David Yes the first problem is my t-online account in Thunderbird which is a pop. Unfortnately the settings were wrong, so that the incoming Emails were deleted after 14 days from the t-online Server. They exist in the t-online account in Thunderbird, but not in my origianal t-online account at Telekom.

It's POP versus IMAP protocol. Maybe you should read this help article https://www.thunderbird-mail.de/lexicon/entry/112-e-mails-von-mehreren-computern-aus-verwalten-imap-statt-pop/ (it's in German). In my opinion IMAP instead of POP accounts would solve both of your problems

Okay, I'm struggling. If the account is POP, why is the sent folder on the server? That would be true only if the account was IMAP. That's problem 2.

On problem 1, you have messages on the PC, but not on the server. The account is POP. To copy the messages back online, you need to create an IMAP account alongside the POP account. Then, you can COPY (not move) the messages from PC to the online inbox. At the same time, since the sent folder, for whatever reason, is on the server, you can copy them from the online sent folder to the PC's sent folder.

@Mapenzi, I concur, but he seems to prefer POP. My inference is that it was IMAP initially.

Hello David,

thanks so far.

I could partly solve the problem 2. Instad of a pop account I created an imap account in Thunderbird. So now I have two accounts withe the same Email adress in Thunderbird. One is pop, the other one is imap. The imap account has the send folder that I need. So in thunderbird I can generally read send messages now. Is there a possability to merge the two accounts or move the send folder from one accout to the other, so that I only use for example only the imap account?

Now after reading the articel I think I prefer imap more than Pop. But when I put the settings in Pop, that he should never delete messages, Pop would also be fine with me.

Problem 1 its more difficult and I can`t really understand your suggestions. As I wrote the settings in my Telekom/t-online account are Pop AND Imap (see above secureimap und securepop). Both seems to be activated. And problem 1 has nothing to to with the sent folder but with the inbox. So I don´t understand your suggestion concerning problem 1. Maybe you mixed it up. But generally I think the way to copy the inbox in thunderbird to my computer and try to copy it to the inbox of t-online/Telekom should be the right way. The question is how.

to get the inbox folder from PC to the server, you could hightlight all the message in the inbox folder in POP and rightclick and select COPY TO the inbox folder in the IMAP account. That works if there aren't a lot of messages. If there are thousands of messages, I suggest creating a manual filter to select the inbox on the POP folder and COPY TO the inbox on the IMAP account. When done, all will be in IMAP and you could continue that way.