Any transactional email recommendations?

I'm choosing a solution to send emails from my app. I want to send a low volume of simple emails and I want it to be cheap and low complexity and low problem causing. Sending emails from your own app has IP reputation hassles but there are external services that look promising like mailgun, mailchimp, postmark.

I've used sendgrid for years but you constantly get put in IP blocks with spammers and then they tell you there's nothing they can do, but your emails (password reset etc) don't get delivered, causing frequent frustrating problems. 

Does anyone have any recommendations?

I never had any problems with Mailchimp, it’s just a very expensive solution sometimes. Recommended if you’ve got money burning a hole in your pocket.

I use Mailgun in all my projects and i'm happy with them.

Its a bit of a blocker so I decided to pick postmark for now. Thanks for the suggestions! It might even have a free tier for low volume where im at now. mailchimp was starting at 20$ per month, postmark 10$ for transactional emails

That's what I was about to suggest, I've been using Postmark for 2 years and I'm very happy with it.

I've been using Mailjet for over a year now. So far so good if people are looking into more alternatives :p

Mailjet looks really good for my usecase. Thank you for the recommendation @denemio !

For transactional emails, I have used AWS SES, that has a 62k emails / month free tier if your server is on EC2, and the paid tier is always cheaper than other tools: 0,10 USD per 1000 emails ($1/10k). It's not more complex than Sendgrid or Postmark: you validate your domain, ask for approval, then you send your transactional emails through SMTP or API credentials, + free tier is always a good option 😬