If the mail server is closed, the incoming mail will wait for delivery.

[H.c.K]

Hi, maybe there is something like this in general but I want to ask. If the mail server is closed, can we hold this mail on the pmg side? Let the mail server deliver pmg when it opens.

 

[Stoiko Ivanov]

I hope I understand your question correctly - but yes (this is a general feature of SMTP)
if your downstream server is not reachable, PMG holds/queues the mails and tries to deliver them at a later point.
In the default configuration it keeps the mail for 5 days before giving up on delivering (then it deletes the mail)

I hope this helps!