Yes, this feature isn't obvious but delivery to your mail host can be paused for up to 5 days at a time without bouncing "failure" notices back to the sender.

First, some background details. When your mail host is unreachable or deferring mail, SpamHero will automatically spool your messages and continually attempt to deliver them as soon as your server is back online.

You can force SpamHero to begin spooling your mail by removing your Delivery mail host (in the control panel, under Settings). Be sure to take note of your delivery host before removing it.

Some things to be aware of:

• Mail that has been queued for over 5 days will generate a "failure" notice to the original sender. Even if that happens, those messages can still be delivered after your mail server is back online.
• The control panel will display a banner to remind you that your Delivery mail host is missing.
• The internal delivery logs may temporarily show an error status but will automatically recover when the Delivery mail host is restored.