I'm making a mail client which work POP3 and IMAP. I'm programming the client in C++ with vmime api. My question is: What is the best way for synchronizing mail?
I think that identificator is good way but I don't know what is the best identificator for synchronize mail:
message-ID is the easiest to use but is it possible that there are two identical message-ID? Same question for UID (IMAP) and UIDL (UID)?
can you help me? Thank you in advance.
While Max is right in saying that a tuple of (FolderName, UIDVALIDITY, UID) will never ever refer to any other message, there's unfortunately no guarantee that a given message will be always referred to only using that same tuple. Servers are allowed to bump the UIDVALIDITY, and there's no standard way of providing unique identifiers which persist across message moves or identify duplicate messages.