Sparkpost: sending from my domain to my domain

[BassMan]

Hi,

I have a problem with bounce email with Sparkpost. When trying to send from A@mydomain.com to B@mydomain.com I get a bounce. Sending from mydomain.com to other emails works normal, just from my domain to my domain. This is a problem when you have forum email as A@mydomain.com, contact email as B@mydomain.com and a user with C@mydomain.com.

Not sure how to set things right. Like said, all works normal except sending from my domain to my domain.

Any help appreciated.

 

[Sim]

What does the bounce message say?

 

[BassMan]

This:

50-"JunkMail rejected - mta# [a.b.c.d]:40683 is in an RBL: 550-IP a.b.c.d is UCEPROTECT-Level 1 listed. See 550 http://www.uceprotect.net/rblcheck.php?ipr=a.b.c.d"

 

[BassMan]

Or this:

550-"JunkMail rejected - mta209.spmta.com [35.163.121.33]:40683 is in an RBL: 550-IP 35.163.121.33 is UCEPROTECT-Level 1 listed. See 550 http://www.uceprotect.net/rblcheck.php?ipr=35.163.121.33"

 

[Sim]

Your sending IP (presumably from SparkPost) has been blacklisted by your mail provider who hosts your @mydomain.com emails. Basically, your mail provider is using a simple DNSBL and your sending IP is on it.

This is the risk you face when using shared IPs on an ESP like SparkPost.

You can try contacting SparkPost support and asking them about the blacklist - you may be able to get your account moved to a new shared IP pool. Alternatively, if your sending volume is high enough, consider upgrading to a paid account with a dedicated IP (not worth it for low sending volumes though).

 

[BassMan]

Hm, not good.

Your sending IP (presumably from SparkPost) has been blacklisted by your mail provider who hosts your @mydomain.com emails.

Not sure if I understand it right... So my host blacklisted it? The email domain is the same as the forum domain. And it happens only when sending from my email domain to my email domain.

Well, on this particular forum I have around 10.000 emails per month. Not sure if it's worth it. Maybe I'll try with Mailgun then. Do you think this can happen with Mailgun too?

 

[Sim]

I'm not seeing any listing for 35.163.121.33 right now though

 

[BassMan]

I'm not seeing any listing for 35.163.121.33 right now though

Me neither. And that IP is from Amazon? ...

 

[Sim]

Do you think this can happen with Mailgun too?

Yes, it can happen with any ESP who uses shared IP addresses for sending emails.

If one of their users sends emails which are deemed to be spam, it can lead to the sending IP being blacklisted - which means that anyone else in that sending pool will also have difficulty getting emails delivered to a mailbox where they check the blacklists to determine is mails are likely to be spam.

 

[BassMan]

Understand, but I don't understand why it only happens in this scenario: only when sending from my email domain to my email domain.

Other users are getting my emails normally.

 

[Sim]

Me neither. And that IP is from Amazon? ...

No - well yes, it is from Amazon, but it's used by SparkPost (they use Amazon AWS for their infrastructure) ... 35.163.121.33 = mta209.spmta.com ... "spmta" = "SparkPost Mail Transfer Agent"

 

[Sim]

Understand, but I don't understand why it only happens in this scenario: only when sending from my email domain to my email domain.

Other users are getting my emails normally.

Who is your email hosted by for that domain?

 

[BassMan]

https://www.neoserv.si/, a company in my country. Very satisfied with them.

 

[BassMan]

I'm also using CloudFlare if that matters.

 

[Sim]

https://www.neoserv.si/, a company in my country. Very satisfied with them.

Well, it's them who are blocking emails getting delivered to you - you may want to see if there is a way to whitelist your email addresses or something.

 

[BassMan]

Ok, thank you for clearing this out for me. I'll check my settings with them.

 

[Sim]

Just remember that SparkPost uses a pool of IP addresses - so it may not actually be the 35.163.121.33 address that is currently causing you problems?

When did you get that bounced message? If it was more than a week ago - it could be that the address was on the blocklist at the time, but has since been removed.

If mail sent from 35.163.121.33 is still being blocked by neoserv.si, even though that IP address is not on any blocklist - then that seems to be a problem at the neoserv.si end - perhaps they are caching DNSBL lookups and haven't refreshed to see that that IP is no longer blocked?

 

[BassMan]

I'll write to them now and report back with information. This started to happen about a month ago. Till then it was all fine.

It's funny that sometimes emails go through, but mostly I get a bounce status.

 

[Sim]

It's funny that sometimes emails go through, but mostly I get a bounce status.

Yes, that would be expected - SparkPost will choose an IP from its pool to send each email, whether it gets delivered or not depends on whether that specific IP address has been blocked.

 

[BassMan]

Actually, my host says this is a thing with Sparkpost or UCEProtect. They need to remove IP from the blacklist.

So, not sure what to do, Sparkpost does not provide support for free accounts, so I'll try with MailGun and see how it goes.