We have had two separate instances of Mailgun blocking our account without reaching out, forcing us to upgrade the account to have access to chat support in order to resolve the issue in a reasonable time. They seem to only respond tickets once a day at best and make their best effort to wiggle out of any effort to help you get back to sending in any haste.

The first time was a mistake on their part when they switched plan tiers and our payment was not processed correctly, they fixed it entirely on their end and did not admit to the problem in the slightest. After this event we made sure to have an intermediate queue on our end in order not to have emails sent into oblivion.

The second time one of our users mass reported a bunch of old emails at once which triggered something that instantly blocked us. Even if we have very low reporting in general (no marketing emails) a single user was able to effectively kill sending of emails to all other users without any forewarning.

After that we forced ourselves out of the platform. When we look for a transactional email sending service, we expect at least an effort on the service to keep the api working while we resolve any issues that arise in a timely manner.

This happened to us a couple weeks back. One day I woke up and our domain had been blocked from sending and receiving. We upgraded our account temporarily to get phone chat support, and what happened was they added some filters which unintentionally got triggered by incoming spam. It was completely their fault, and they fixed it in a few minutes, but they couldn't give me much more detail. Not enough for us to leave Mailgun -- everything else has been great -- but it was very concerning, and I am sure many other accounts were affected.

Can you email your ticket number to josh@mailgun.com and I'll take a look? This definitely isn't typical and I'll get this resolved immediately for you.

Thanks Josh. Our account has been unfrozen, and I've been given some assurance that it'll not happen again for us. Cheers.

Similar thing happened to me as well. I added another domain for a completely different project and their spam detection locked my account completely, including my main project I've been using for a long time before without any issues.

Got account unlocked after six hours of downtime though, but I changed email provider since then.

I had this and the whole account was locked too after adding a "suspicious" one. But the delivery/reception was still working for other domains, only config changes were disabled.

It seems they do that on a TLD basis, for example if you add the domain "spammer.xyz", it will probably lock your account because ".xyz" TLD is considered risky.

They support always fix the problem, but we're always locked a few hours, this is super annoying.

What did you change to?

Postmark. Very happy with their service so far.

I'll chime in for Postmark as well.

As a B2B SaaS, our opportunity cost for support (and potential for lost goodwill) due to failed notifications is high, and switching to Postmark noticeably moved the needle. Time is our most valuable and scarce resource, and peer recommendation is our primary marketing device, so the price increment for switching to Postmark is easily justified. Their deliverability and support are stellar compared to Sendgrid, Mailgun, and SES.

Two thumbs up

See also: Fastmail over G suite for your mailboxes and calendaring.

In what way does your B2B use Postmark? And do you use Fastmail for your company mailboxes? If so, why not just use Postmark to forward emails?

Another vote for Postmark here. They are more expensive, but worth every penny.

I do wish they would let you choose the region where the server is located though, like Mailgun does.

Just a word or advice: if you're only sending to 200 people you might not need mailgun.

You can use gsuite programmatically for easy inbox management with the Gmail API.

How is paying for G Suite and using their API instead any different?

Mainly from a user experience and customer service perspective:

You can hire a non technical person to manage your inbox without having to code as much to connect with your systems.

If you have problems with G suite, you are a paying customer and you get support from Google. There's a phone number you can call and get your problems solved.

I had a worse experience with mailgun that almost made me lose my job. Our domain was blacklisted for sending spam. I think mailgun's server was hacked at that time because our Api Key was kept securely using the best practices. I dont want to use Sendgrid because of bloated and slow UI but I had no choice.

If this is a recent occurrence, I'd be happy to have our application security team take a look. To be clear, there hasn't been any kind of breach, but our customers are often targeted in phishing schemes that results in the disclosure of account credentials. We're continually adapting our defenses, but this is responsible for the majority of credential leaks.

There's one really easy step you could take that would make a huge dent in those phishing schemes:

Detect and block phishing emails that are forwarded through your service. Right now, I get several messages forwarded per day from "Sam at Mailgun" (actually a variety of external senders) trying to get me to log in to review various (nonexistent) problems with my account.

> our customers cannot contact us at all

I thought mailgun was for delivering emails? How/why are they your MX?

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.

IIRC Mailgun is one of those services that let you develop your app to use their api (i.e get some skin in the game, let you do a small fraction of the free-tier emails) then instantly locks your acc until you add a card for ID. The first IP they put me on was also blacklisted by Hotmail, meaning emails don't even get through to the user's spam box.