[PHP] why Imap_open delay ??

hi When connecting to a imap server ,it always takes a 20 second delay. I use like this : why this happen???

[PHP] why "imap_open " delay a long time ?

hi I have worked with imap functions for a long time . When I use "imap_open" connecting to a imap server ,it always takes a 20 second delay. I use like this : why this happen?