PHP IMAP vs Webklex
Understand why mailbox account connections always use the bundled Webklex IMAP driver.
Mailbox account connections always use the bundled Webklex socket-based driver. The native PHP IMAP extension is not used for account connections and is not a hosting requirement.
Why Webklex is fixed for accounts
Account connections use Webklex so destructive IMAP mutations can target exact UIDs. Native php-imap exposes mailbox-wide expunge behavior that can remove unrelated messages another client marked as deleted.
What diagnostics may show
The general driver diagnostic can still report whether native php-imap exists. That diagnostic does not change the driver used for saved mailbox accounts. No PRESSEDMAIL_IMAP_DRIVER constant or filter switches account connections away from Webklex.
Hosting requirement
Do not ask a host to enable php-imap for PressedMail account connections. Focus on PHP 8.2 or newer and outbound access to the provider's IMAP and SMTP ports.