This shows you the differences between two versions of the page.
Previous revision | |||
— | how_to:vpop3_deleting_messages_as_old_messages [2018/11/14 10:45] (current) – external edit 127.0.0.1 | ||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ======VPOP3 Deleting messages as ' | ||
+ | |||
+ | If VPOP3 says ' | ||
+ | |||
+ | With the POP3 protocol, the POP3 server will give each message a ' | ||
+ | |||
+ | Unfortunately, | ||
+ | |||
+ | For instance: | ||
+ | |||
+ | - message arrives and the server gives it unique id ' | ||
+ | - One POP3 client logs onto that mailbox downloads the message and remembers that it has downloaded message ' | ||
+ | - another POP3 client logs onto the mailbox downloads the message and deletes it from the server | ||
+ | - a new message arrives, and the server re-uses the unique id ' | ||
+ | - the first POP3 client logs onto the mailbox and sees that the message ' | ||
+ | |||
+ | Because of this possible ambiguity, **most** POP3 servers will not reuse unique IDs, or at least won't reuse them within a short timespan (VPOP3' | ||
+ | |||
+ | There is another issue which can sometimes happen with some ISPs which is that sometimes a message may re-appear after being deleted, or may occasionally just spontaneously disappear and then reappear. Because of that, VPOP3 will remember unique IDs which it has seen for a few days even after the message has disappeared (in case it comes back again, to prevent duplicate downloads) | ||
+ | |||
+ | Both of these issues together can cause VPOP3 to think that new messages are old messages, even if it is the only POP3 client accessing the ISP's mailbox: | ||
+ | - message arrives and the server gives it the unique id ' | ||
+ | - VPOP3 downloads the message and remembers the unique id | ||
+ | - a few days later, VPOP3 deletes the message, but still remembers the unique id | ||
+ | - a new message arrives, and the server re-uses the unique id ' | ||
+ | - VPOP3 connects again, sees message ' | ||
+ | |||
+ | The ideal solution to this problem is for the ISP's POP3 server not to re-use unique ids, but that would require a change at the ISP. | ||
+ | |||
+ | If it is not possible for the ISP to fix the problem on their server, you can tell VPOP3 not to remember unique IDs once it has deleted the message once. You can do this by going to the VPOP3 settings -> Settings -> Misc Settings -> Advanced, and set **Hold Obsolete UIDLs for** to "0 days". Note that this will not solve the ambiguity described above because of the re-used unique ids, and it also causes the possibility of messages being duplicated if a deleted message becomes undeleted again for some reason. | ||
+ | |||
+ | |||
+ | (see also [[Mail Not Downloading from ISP]]) | ||