TL;DR: Some SMTP issues are not logged as event, this can lead to multiple email sending without noticing it.

Let me tell you a (true) strory:

A customer calls us to let us know he receives the same email multiple times from us. We find this really weird… but, hey! He take time to notify us: let's dig into our multiple level of logs… We found nothing speaking to us… So we ask for an example to our customer… He send it back to us… We, now, can determine what mail was send multiple times… And, what a surprise when we jump to the mail history we see the following events:
Accepted, Opened, Opened, Opened, …

Look: no _delivered_ event while the mail has been opened.

Asking for insights to Mailgun support, we get the following response:
```
Every time we submitted the request it failed internally with the following error,

> data write failed: write tcp4 A.B.C.D:10277->E.F.G.H:25: i/o timeout

Because we didnt get delivered response we continued to attempt delivery until we receive the delivered response. This would be the cause of the multiple deliveries.
```
(where A.B.C.D is our sending IP and E.F.G.H the destination MX IP)

So we ask why we did not get the error event:
```
Our apologies for any inconvenience. Unfortunately, these types of failed events are actually classified as internal and are not public facing to the customer.
```

So… I think that this is an issue: we have no feedback on sending issue, we cannot monitor them, and over all, it could hurt our reputation without knowing it.

Recently, I setup an SMTP account. I used a strong password generator. That password had special characters in it. When I went to use it, I got a very generic message that said Mail Gun does not love my credentials. The could be solved one of two ways. 1) Preferred - Have validation on the SMTP box when you create the credentials to not allow for special characters and a message to that effect if some are used. This would stave off this situation right at the beginning. 2) Not preferred but workable - Change the error message that comes back to say "You have special characters in your password and that is a no-no." I really like 1) the best. Thanks for listening.

We are in process of cleaning our mailing list to increase our sender score.

When contacted the support about this, i got reply from Ryan and Chris:

1. Ryan Said:

There isn't a direct easy way to remove these users from multiple mailing lists. I would look through our API and Develop the best way that works for you.

You can do something like: if ```email``` exist on ```mailing list``` then ```delete``` else ```break``

2. Chris Said:

Feel free to submit this request here to be considered for development.

Temporary Solution using API:

So as Ryan suggested when i go throught the api, There is three step process using mail gun api to achieve this:

1. Get Bounces (Get a email id from address collection)

2. Listing members: (Pass that mail here )

3. Remove a member: (If exists remove that mail)

Requesting to Add this feature in Dashboard:

make process simple:

Example:

press find bounces button which list all the bounced email id, then select each or select all and press remove button, then it automatically removes all bounced email from all the mailing list or from the selected mailing list.

Hope that helps.

Thank you.

Not sure if this is the correct place to post this but it's where live chat told me too. This seems more of an oversight/bug then like "feedback" but apparently you need the Admin role to see and use the Clear Domain Queue button in domain settings. That doesn't seem right because I have the Developer role right now and can just about do anything in the UI from creating new domains, assigning IP's, creating and deleting mailing list; I can even delete domains completely YET I can't clear the message queue for a domain?

Clearly that logic doesn't make any sense at all and is not protecting anything as roles are setup for if I can delete the domain surely that's going to clear the queue and everything else associate with that domain. Thus that leads me to believe the permissions set for that button are not correct and was overlooked and should be corrected to the appropriate level to view.

I am using a route to post incoming message to an API for processing. If the processing is successful, all is fine. If there is a processing problem, Mailgun correctly retries to post after a period of time.

I would like a way I can see all the emails that are waiting to be re-tried? I can see them in the log marked as "Will retry in 900 seconds:", but it is difficult to determine which emails are *still waiting to be processed*.

I want to see a list of everything that is currently waiting to be retried. That way, I can determine if there is a bug in my processing, or if I need to add more compute power to process the queue.

Pros:

- Good customer service

- decent documentation

- easy to get going

Cons:

- Mailgun feels like its from the 80s. the UX is drab, and really ugly.

Been using AWS Heroku, and Google Cloud lately, and those interfaces feel like a rocket ship in comparison.

- Alot of what mailgun feels like a black box to me. This is my first real time using transaction email, but their is a heap that mailgun could teach, and be transparent about what they do under the hood.

- Setting up dns could be better. would be good to be able to download a file/text and upload directly to cloudflare or cloudfront