Sometime I need to move email from an old software to a new one, like from Windows Live Mail to Outlook/Thunderbird, and external conversion software fail to convert emails, I'm forced to use an IMAP server where to place emails than download in new software, so I'm looking for a portable IMAP software so I can do that directly local.
Can you help me?
IMAP is communication protocol which is provided by mail server to be run between the server and the client.
So you would need to run a server and install a mail server on it.
I have also Windows Live Mail and TB, there is nothing to convert. You just connect both, the LiveMail and the TB to the same mail server and have all you want.
I know, now I'm forced to use a full mail server like hmailserver but for me it's enough to have an IMAP connection to a basket where put all the mail than I connect that IMAP to thunderbird and move that mail to it, than I can delete that IMAP server
Windows Live mail --> copy/move emails to --> Local IMAP server temporary --> copy/move emails to --> thunderbird
IMAP is provided by a mail server. The server has to be running. Basket or inbox or what ever you call it is a function provided by a mail server.
So you need a mail server running and offering communication by IMAP.
So you need to run a mail server. This is not a simple job, however it can be done. There can not be anything like that portable, but you can download some mail servers elsewhere in the net. Install it on a PC, run it in localhost.localdomain.
Then you need to send the mails to the server by SMTP protocol, otherwise you can not copy anything 'to the server'.
So yes, you need to send those mails to the server.
Once the mails are on the server, you can access them by IMAP or POP3. Reading by IMAP the messages will remain onthe server unless you run an expunge command. Reading by POP3, you can delete the massages directly after reading them, but this is not compulsory, you can leave them on the server as well.
There are mail servers also for NAS servers like Synology.
I also do not understand why you want copy something back and forth. The mails you read in your LiveMail or TB are also coming from a server. You can just connect TB to the same server and you have the mails here. In IMAP you anyway do not really download mails, they reside in the server and you just get header or copy of the contents on demand.
You have a mail provider.
You want use this mail provider.
So just connect any mail client to the server of the provider and you have all mails available in all mail clients.
here is the famous small mail server: