imap_errors

This function returns all of the IMAP errors (if any) that have occurred during this page request or since the error stack was reset (PHP 3 >= 3.0.12, PHP 4, PHP 5)
array imap_errors ( )

This function returns an array of all of the IMAP error messages generated since the last imap_errors() call, or the beginning of the page. When imap_errors() is called, the error stack is subsequently cleared.

See also: imap_last_error().