If you notice a consistent delay when trying to receive certain emails, but other emails arrive instantly, your mail is likely being filtered by Greylisting.
What is Greylisting?
Greylisting is an anti-spam tool used by TOAST.net to verify that an incoming email is coming from a legitimate mail server.
How Does Greylisting Work?
Greylisting works like a "security check" that asks new senders to prove they are real by simply sending the message a second time.
When an unknown server sends you mail, our mail server temporarily "defers" it.
Legitimate mail servers automatically try to resend the mail after a delay, whereas most spam bots will just "give up" and try a different target. This helps filter out a large amount of spam email.
Once the legitimate mail servers retry to send the mail, the message delivers and our system then "remembers" that server and future emails they send will not be delayed.
How Do I Avoid Greylisting?
While Greylisting is an excellent anti-spam technique, some users may experience issues in the case of one-time code emails where the code expires after the Greylisting delay and becomes invalid. To by-pass Greylisiting for a specific sender, you can simply mark the sender as a Trusted Sender. You can do so by opening an email from the desired sender, and selecting the Trust Sender button from the actions menu.
In the case that trusting a sender is not working, you can try the following step.
Warning: Only perform this step as a last resort:
If you need to urgently receive an email that you believe is being blocked due to Greylisting and trusting the sender is not working, you can temporarily disable grey listing by going to Settings > Account > then disabling the Greylisting button in the User box. Make sure you click Save at the top once the change is made:
Once you get the email you desire, re-enable Greylisting the same way. Having Greylisting turned off can result in more spam coming in.