Email workflow

[TLALD11]

Hello everyone,

is there an overview of how Postal processes mails (Postal Process Flow/Workflow) and what the different statuses mean (bounced, softfailed, hardfailed)? It's mainly about mails where an error occurred.

I saw that mails are in the messages table and can have different statuses (e.g. send, bounced, softfailed, hardfailed), then there are delivery messages in the deliveries table with a status and message_id = id. For hardfail and softfail, you can read the details directly from the database. For a bounce message, it gets more complicated. First, look for the message ID in deliveries, pay attention to the bounce status there, read the new msg ID there, and it's best to query the message details via API. So now I have all the information about what went wrong.

1. but how does Postal process mails with the different statuses bounce, softfail or hardfail, held and holdcanceld?

2. Which emails does Postal try to resend and which ones doesn't it? And how does the status then change from bounced or failed? Or does the status remain the same?

3. When is the status held and goes to status HoldCanceld? What happen with a message with status holdcanceld? IN deliveries there is a message with "The hold on this message has been removed without action."

4. What is the status of an email that is initially bounced and then successfully resent?

5. Do bounced emails remain bounced permanently?

6. What about the suppression list? The list contains all email addresses that have had multiple (18?) email delivery errors? Are these bounced, softfailed or hardfailed messages or does it not matter?

7. What happens if you manually delete an address from the suppression list? Are the emails (status held) that have accumulated during that time automatically sent again? Or what is the status of emails that are supposed to be sent to an email address on the suppression list?

Sorry for the many questions. But basically it's just about the "workflow" of how Postal processes mails where an error has occurred.

Thank you very much

[willpower232]

No worries, Postal is definitely a little different and easily misunderstood if you haven't used it before.

There isn't a diagram of the flow but I can answer your questions:

1. softfail messages are usually retried but everything else is where a message ends up and is not changed further unless you press the resend button manually, you can get webhooks of status changes to follow along locally

2. softfail messages are retried a certain number of times, 18 by default, with longer gaps between each retry to see if that helps the situation. If a message cannot be retried, or has retried too many times, it should go to hardfail

3. When a message is held, it has a release button to carry on as if it has never been held. After 30 days I believe the hold is cancelled so the message is removed from the held list and could only be sent if the resend button is manually clicked. Once a hold has been removed from the message, it must be resent manually in Postal or wherever it originated from

4. If Postal thinks a message is bounced then it is not retried, the message was successfully delivered and then a bounce message was received by Postal later. If there is a temporary issue in delivering the message, it is set to softfail and tried again later automatically

5. Yes, if Postal has a bounced message, it would have to be resent manually

6. I think it is just hardfail messages that put the email address on the suppression list, I'm not fully sure but the idea is if Postal really can't deliver the messages then it stops trying for 30 days to give the situation chance to recover

7. If an email address is on the suppression list then all future messages are automatically held until the email address is removed from the list. Held messages are never automatically retried, if you go to a held message and click on send and the send is successful then the email address is removed from the suppression list but other messages would have to be manually released

Hope that helped!

[TLALD11]

Hello thank you very much.

That helps me a lot.

What happens to messages with status bounce? Will they be sent again or will they remain from Bounce? We have a manageable bounce rate of 0.2% with around 1 million emails per month. IN the messages table they are listed with STATus Bounced. I've already tried the webhook and it works too. Caught various events. For example, when a BounceMessage is received, can you delete this email from the message DB or are there any problems? Are bounce messages put into the MailQueue again? (Postal queued_messages table)

I can't see anything changing automatically in the Bounced status. But I'm worried about simply deleting messages and deliveries with the status Bounced.

[willpower232]

I think they would stay in bounce, as far as Postal is concerned, the message was fully sent and accepted by the receiver but bounced later so Postal doesn't think it has to try sending the message again.

If you want to resend it, you would have to trigger that then you received the bounce webhook.

You can delete the message from Postal if you want I guess but Postal clears out its data anyway so you probably don't need to worry about it.

[TLALD11]

Summary:

Hardfail --> Stop Sending

Softfail --> new delivery attempt (max number in postal.yml), then harfail and on suppression list (if configured).

Bounce --> Stop Sending (possibility to send email again manually). Status Bounced remains

Hardfail and suppression list --> All incoming emails remain in hero status. On supressionlist eg, 30 days (postal.yml) and after this days all held message will resend

And softfail or hardfail is depending on the receipient mailserver answer?

To delete of messages

We have a function that presents bounces and failed messages to colleagues in one view and then processes them. When the action is completed, the entry can be marked as completed and if necessary. the message can be deleted directly from the Postal DB. That's why you could use the bounces, as well as if necessary. delete the hard-failed messages and the associated deliveries directly. I would leave the soft failed messages as there are multiple automatic delivery attempts. Only when the message goes to hardfailed and has been edited could it be deleted.