Oh! That's what it is. I just thought some websites just took longer to send an email to my unknown domain. I see that the only way to disable greylisting is t

Oh! That's what it is. I just thought some websites just took longer to send an email to my unknown domain. I see that the only way to disable greylisting is to configure the underlying tool [1]. But it also means that SPAM will increase a lot. [1] https://discourse.mailinabox.email/t/how-to-turn-off-edit-grelisting/4984?u=s4_hosting https://discourse.mailinabox.email/t/how-to-turn-off-edit-gr...