# Anyone having issues sending to comcast.net addresses using mailgun? \<SOLVED\>

**URL:** <https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381>\
**Category:** Self-hosting\
**Tags:** hosting\
**Created:** [2016年六月24日 02:36 UTC](https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381 "2016-06-24T02:36:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![boomer196](https://avatars.discourse-cdn.com/v4/letter/b/97f17d/32.png) [@boomer196](https://meta.discourse.org/u/boomer196)\
**Post date:** [2016年六月24日 02:36 UTC](https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381/1 "2016-06-24T02:36:03Z")

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I switched to mailgun after mandrell went away as suggested in discourse. However, now all of my emails sent to [comcast.net](http://comcast.net) email addresses are failing with: “550 5.1.0 Invalid sender domain”. It works for every non comcast customer though.

This obviously isn’t an issue with discourse, but I was hoping someone might have some insight. I called comcast and they were completely useless and have opened a ticket with Rackspace. We will see what they say. In the meantime…

Thanks for any help!

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**Author:** ![boomer196](https://avatars.discourse-cdn.com/v4/letter/b/97f17d/32.png) [@boomer196](https://meta.discourse.org/u/boomer196)\
**Post date:** [2016年六月24日 23:46 UTC](https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381/2 "2016-06-24T23:46:51Z")

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I figured it out. I thought I would document it here in case anyone else needs help in the future.

The sender of the email was coming across at comcast as ‘xx@mg.mydomain.com’, which comcast was trying to verify.

I needed an additional MX record. I use Google Apps for normal emails, but also Mailgun. I had all the Google Apps MX records, but what I had to do was add an additional MX record with a subdomain of “mg” for mailgun, which I just pointed at google server. Here are my MX records, which seem to now be working:

```
MX Records
Mail Server	Preference	Subdomain	TTL	
aspmx.l.google.com	1 Default	
alt1.aspmx.l.google.com	5 Default	
alt2.aspmx.l.google.com	5 Default	
alt3.aspmx.l.google.com	10 Default	
alt4.aspmx.l.google.com	10 Default	
aspmx.l.google.com	20	mg	Default

```

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**Author:** ![russellbal](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/russellbal/32/206658_2.png) [@russellbal](https://meta.discourse.org/u/russellbal)\
**Post date:** [2021年一月20日 15:32 UTC](https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381/3 "2021-01-20T15:32:14Z")

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嘿，谢了伙计！今天我也遇到了同样的问题，涉及 Comcast 用户和 Mailgun。现在我得想想如何处理 MX 记录。

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**Author:** ![jod.z](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jod.z/32/142444_2.png) [@jod.z](https://meta.discourse.org/u/jod.z)\
**Post date:** [2021年三月17日 22:05 UTC](https://meta.discourse.org/t/anyone-having-issues-sending-to-comcast-net-addresses-using-mailgun-solved/46381/4 "2021-03-17T22:05:17Z")

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也想表达一下感谢，感谢在这里分享答案！问题很容易就解决了。