Here we go again, mails blocked due to blacklist

One problem with renting servers is that one often gets IPs that are on a blacklist; and this goes for any provider you rent from; any provider as they can not just throw away every IP used by a spammer; IPs cost money.  They rent to someone that spams, the IP gets on the blacklist, the server provider drops the client based on abuse, then the IP gets assigned to a new client.  Getting your IP off these blacklists is not always easy; I think I am still fighting with AT&T over blocked emails to their mail server.  If the mail server is using Spamhaus lists forget it.

The question I have for the community is how are others dealing with the Dolphin mail issue?

Some ISPs are horrible. Optimum is probably the worst - they will block you or your domain for no clear reason. They have no way to contact their mail team directly besides being transferred around their customer support, and even then, it's slow and there's no guarantee they won't re-block you. They claim they only block you if you're listed on specific lists, but this is simply untrue.

We never allow our servers to be used for only mail, and can figure out quickly if a new order will be used for this. We check all our IPs for issues, and run blacklist monitors and also receive any abuse reports. We understand the annoyance blocks can cause. Sometimes because of a new IP or sender, some mail servers will also not allow fast or reliable delivery. For any issues that can't be immediately resolved, I often recommend to use SendGrid's free plan with the SMTP Mailer. Problems clear right up.

Hi GG. I'm an owner and co-founder of two companies, one of them is specifically related cloud based Email Filtering, the other is related to Web and dedicated server hosting.

I won't mention them here but if you PM me I'll give you the website details.

Our web and dedicated server hosting systems use, as the outbound SMTP relay (ie. SMART Host), the services of our cloud based Email filtering service. The Email filtering service has inbuilt protection from spammers trying to use the service to send spam (for obvious reasons) and if any client uses our outbound relay and gets infected resulting in accidentally sending spam, the service manages that too (it can limit outbound emails per x minutes from SMTP floods etc).

One of the newer features we'll be introducing this weekend is the ability to "rotate" outbound IP's, so in the remote chance one of our outbound IP's get blacklisted, we can tell our service to stop using that IP and use another from a pool we assign, minimising any type of RBL outage for customers.

Due to the volume of outbound emails sent through the Email filtering servers, our service is recognised and trusted by the largest Email providers and RBL lists in the world ie. we should never be blocked by anyone from receiving emails from our servers. We also have formal reporting agreements with various RBL lists who accept our spam reports to block IP's, URI's, etc.

At the end of the day, all your problems will be solved if you use an outbound SMTP relay service that's dedicated and trusted, the tighter email security gets the more and more this will become the norm. It also goes without saying, it's always better to use an SMTP Relay than send directly from the server yourself.

Thanks Nathan.  Another problem is getting caught up in lists that block whole ranges of IP address.  Some mail providers are easy to work with, others, like you mentioned, make it almost impossible to get the IP address whitelisted. Being a small company, it is easy for them to just ignore you.  If you are big, like Google, you have more weight to throw at them.  I was actually surprised this time; outlook removed the block after reviewing the website.

I will look into SendGrid. 

If anything I learned about emailing so far is that its not worth doing it yourself, for most people. its best to just off-load it to someone like mailgun.

if your getting blocked by AT&T its probably because you haven't configured rDNS on the IP address that the mail server is on. this is actually the most common problem with running your own mail sever. you would probably have to ask your host to do this or the can forward the NS lookup to your own DNS server.

basically most providers are rDNS lookups to verify its a legit mail server because you cant fake it without getting the ISP involved.

To explain it... the receiving mail server will query the source IP address's name server and it wants to see the same thing as the sending smtp host name.

SMTP Host Name > example . com

MX > mail . example .com

DNS > mail . example . com > 1.1.1.1

rDNS > 1.1.1.1 > mail . example . com

Also don't forget your txt / ptr dns records and DKIM

One other tip for maintaining good standings is to setup your email auto reply, support questions and if they email your 'no-reply' email... etc... anti spam hubs do look at the in-and-out email traffic in determining the over all trust worthiness of the source. one way traffic lowers your rank.

Yes, I know and have set up rDNS.