[brianmcconnell]

Long time App Engine user here. If you're sending email as part of your app, I'd recommend using Mailgun (or similar services). You can set up DKIM, inbound routes, etc, and generally have more control over how your mail is processed. I never got the impression App Engine really wanted to be in the email delivery business, so if that's important to you, there are tools that are focused on that (and free up to a monthly quota). My $0.02.

[metachris]

I've recently compiled a list of free transactional email services with a feature comparison: https://www.metachris.com/2016/03/free-transactional-email-s...

[siva7891]

I completely agree with your recommendation on Mailgun. Using it for past 4 months, never had a problem with their service.

[manyxcxi]

Love Mailgun. You can configure it to just be a very easy mail provider or use the APIs to send mail and turn on all kinds of things like campaign monitoring, tags, click opens, etc.

The best part for me when using it for customers has been the bounce/click through rate tracking. When someone asks me, "how do I know they got it?" It's incredibly nice to point them to the dashboard and show a less than 1% bounce rate (people putting in bad email is almost always the reason) with a log of every single email sent.

Most my clients get this service for free because their volume us low enough. They have quite a generous free tier.

[wastedhours]

+1 as well, after the changes to Mandrill recently, was looking for a new provider and can also recommend Mailgun (at least, for ease and configurability in set up and testing so far, not yet in production).

[pritambarhate]

Yes, Mandrill should have kept the free quota after DKIM and SPF verification. Now, I will be trying out the competitors (Sendgrid and Mailgun) and if I find them at par with Mandrill then for paid projects, I might use them rather than Mandrill.

[mrcncpt]

For our clients, the appeal of Mandrill is the Mailchimp Template Editor. I think this is where their focus is going and so if you don't need that, then definitely check out competitors.

[pritambarhate]

Out of around 18 projects, in which we have used Mandrill, only in 1 we have used the template editor. (I think only about half went for paid accounts when the project went live.) Most of our need was simple and quick transactional messages (Registration, Forgot Password, etc.). The main reason we chose Mandrill was ease of set up over Amazon SES. (Even though we had AWS accounts for all projects.)

Anyways, it's up to Mandrill to choose who they want to serve. I really liked the service though. Best of Luck.

[elbigbad]

Thanks for the suggestion! I was having issues with SendGrid and had never heard of Mailgun. Took literally 2 minutes to get set up on Mailgun, add the credentials to my app, and send my first email! It's a super small app so don't need anything fancy, Mailgun is perfect.

edit: Not to say Mailgun isn't fancy, I have no idea if it is or not, I can say that it works in minutes though.