(PHP 4, PHP 5, PHP 7, PHP 8)
imap_uid — This function returns the UID for the given message sequence number
This function returns the UID for the given message sequence number. An UID is a unique identifier that will not change over time while a message sequence number may change whenever the content of the mailbox changes.
This function is the inverse of imap_msgno().
The UID of the given message.
| Version | Description |
|---|---|
| 8.1.0 |
The imap parameter expects an IMAP\Connection
instance now; previously, a valid imap resource was expected.
|
Note:
This function is not supported by POP3 mailboxes.
I would like to point out that, at least in the case of Gmail, the UIDs of emails are changed if they are moved from one folder to another. Even if moved back to the same folder the UIDs get incremented and thus changed.
I found this the hard way after relaying on the notion that UIDs do not change as I found almost everywhere in the docs.Please note that message_id in the header is NOT the UID - and its dangerous to use as many mail progs don't put a message id inBe aware that the uid is unique in a single mailbox. That means a message can have as much uids as mailboxesThe uid will change in case of unsing imap_expunge. Be shure that
all work ist done before using imap_expunge.If you want emulated POP3 UIDL support, then you can either use my imap function wrapper class, or just copy/modify it's header to UIDL hashing method:
https://github.com/cmanley/PHP-IMAP-Client/clarification for Andreas' note about imap_expunge()...
imap_expunge() does indeed change the UID, but only *after* the IMAP stream has closed and then reconnects.
You can use imap_expunge() as many times as you want within one IMAP stream (no reconnects) and the UID stays the same while the Msgno will change with imap_delete() followed by imap_expunge().