Postmark bounce support?

[watchmanmonitor (Allen Hancock)]

I’m a big fan of Postmarkapp.com

We use their bounce API to create tickets when emails need attention.

What would it take to expand Discourse’s Bounce Processing to support Postmark?

See:

Bounce API | Postmark Developer Documentation

[codinghorror (Jeff Atwood)]

We only support adding these sorts of things for mail services that have a free tier. Otherwise it doesn’t benefit enough people.

And for our hosted customers, we handle all email, so there’s no reason to do it for our customers.

[zogstrip]

Also, we haven’t used any “Bounce API” but rather “Bounce Webhooks” which is documented here

Bounce webhook | Postmark Developer Documentation

[wesochuck (Wes Osborn)]

@codinghorror

We only support adding these sorts of things for mail services that have a free tier.

Would you consider a PR for postmark bounce webook support now? mailgun, one of the officially supported bounce providers, has now moved away their free tier. I get the impression that free-tiers are generally going away in this industry: Tell HN: Mailgun lowers free-tier API from 10k to 625 emails per month | Hacker News

[Falco]

A PR would certainly be considered. Please communicate early if this providers differs too much from the current supported ones so we can offer feedback on the mergeability of your approach.

[pfaffman (Jay Pfaffman)]

I’ve got this that I’m about to submit a PR.

Using the test curl command that they document here on my development instance it looks like it will work.

I included spec tests for both hard and soft bounces.

EDIT: I’ve now done tests triggering from their webhook test interface and it looks like it actually works.

I think this should be OK: add postmark webhook handling by pfaffman · Pull Request #8919 · discourse/discourse · GitHub

[pfaffman (Jay Pfaffman)]

It’s merged! Thanks!

[pfaffman (Jay Pfaffman)]

@wesochuck suggests the following changes to Bounce types (see Bounce API | Postmark Developer Documentation for definitions of bounce types, though I’ve included them below).

To hard_bounces add:

• BadEmailAddress – “Invalid email address — The address is not a valid email address.”
• Blocked " ISP block — Blocked from this ISP due to content or blacklisting."

To Soft bounces add:

• SMTPApiError – " SMTP API error — An error occurred while accepting an email through the SMTP API."
• DMARCPolicy – “DMARC Policy — Email rejected due DMARC Policy.”

I think that blocked makes sense, but I’m not sure about the rest. Let me know what you think and I’ll make the PR accordingly.

More info — The Postmark PR to handle webhooks doesn’t work

Sorry, but my PR doesn’t work.

First, Postmark throws away the message-id by default.

Second, the MessageID that Postmark includes in the webhook isn’t the Message-ID that is in the message.

From: Everything you need to know about SMTP (Simple Mail Transfer Protocol) | Postmark

Why isn’t my custom Message-ID being sent through Postmark?

First, please note the difference between MessageID (which is generated by Postmark and cannot be changed), and Message-ID , which is the custom value you’re able to set via an SMTP header. The Postmark MessageID will always be what is returned in the “MessageID” field in webhook event JSON, so that you can identify the Postmark message for subsequent API calls.

By default, Postmark will replace all Message-ID headers for outbound SMTP messages. However, it can be useful to preserve Message-ID values for some applications that rely on them. To ensure that Postmark does not replace your custom or original Message-ID header, include an additional header called X-PM-KeepID with a value of true . Postmark will then pass on any original Message-ID header for the message.

Is there an easy way to add a X-PM-KeepID: true header in outgoing mail? Could that be added to core?

If that problem gets solved, then I’ll see about whether there is a way to have the actual Message-ID included in the webhook payload and process it accordingly.