So you can see my history I don't leave many reviews - positive or negative unless it's really underwhelming or simply amazing.

This, unfortunately, did not live up to scratch. I get that it's a startup, but even from a startup perspective it's not well done.

My biggest per peeves are:
1) Outdated, or barebones hardcoded UI
2) Bad UX. Apparently, they need to annoy with a popup walk-through until you add one mailbox
3) Speaking of mailboxes, every other email warmup tool lets you log in to your GSuite/Gmail and pulls the SMTP data etc automatically. But here, you need to enter everything MANUALLY. Not sure if they would say "this is the best way", but still convenience trumps time. I am not going to go around looking to copy/paste info into the app.
4) Lastly, biggest issue, logging in worse than a rat maze. For the first three times, I had to go through the Appsumo product page to log in. Then they said they're working on it and provided a murlist.com/auth to get in there.

I could be totally wrong here, but this app seems to have been custom written. Because most platforms have a set UI/UX, with proper authentication systems baked in. But someone at murlist thought, let's re-invent the wheel and make things hard for ourselves.