They are actually one of the few services that u can use for programmatically receiving emails. When it works, it just works - but unfortunately the spam thing bit us as well.

Fortunately we were able to get it resolved quickly

We provide that at Twilio SendGrid too: Parse Webhook

Having both phones and email at one supplier sounds risky. If you lock my account it takes out the two major ways a customer can reach us. No thanks.

I use MG for automated email intake too, but I also use sparkpost as a backup email intake.

How do you switch from the primary to the backup?

for our purpose i have two distinct email domains and fwd to both addresses and process which ever hits my servers first.

They provide MX forwarding for delivery, but we use them because it saves us from having to buy a per user email account with gsuite or outlook. It's a little bit of a hassle/hack, but it works well enough in practice. I use a free gmail account that receives forwarded emails from Mailgun, and I can respond via mailgun smtp within gmail.

If I remember right, they recommend using a sub domain and being an Mx.