Are you blocked?

Getting blocked by ISPs can be frustrating. You have done everything you can do but still some emails bounce back due to ISP blocks. Most likely you receive emails from someone that says they never get your emails and/or you check your bounce statistics where it states that you have issues regarding spam related bounces or policy related bounces (but it does not have to be blocks by the ISP). Whenever you find that your emails are getting blocked you need to find out why. Normally you start to get blocked if you send anything that is “not ok to send”. Sometimes its hard to understand whats “not ok”. But just don’t rely on emails marketing laws in your country. Emails get blocked even if someone has set up laws on whats legal or not.

Before you try to get unblocked you need to find and fix the problem. If you don’t fix the problem you will soon get blocked again and you need to do this all over again. And for each time you get blocked again, the ISP will start wondering if you actually are taking care of the problem like you say you do and just not help you the next time you are having problems.

How do I know that I’m getting blocked?

If you are getting blocked by an ISP this will normally be visible in your bounce reports. Normally as policy related bounces or sometimes spam related bounces. You need to understand when an ISP actually started blocking you. That is why it’s always important to check your statistics after each sendout so you understand when the problem appears. Normally you have sent an email to a new or old list or you have sent something people are complaining about because they don’t “like” what you sent to them.

STEP 1 of 4: Understand the problem (and fix it)

Check your statistics for emails with a higher volumes than normal of the following measures:

  • Bounces
  • Complaints
  • Unsubscribes

​The following pages tell you pretty specifically what the ISP requires you to do to get your e-mail delivered and whom to contact if you have questions or problems. These Web sites can also show you the way to go when you need to write the e-mail to begin the resolution process.​

  • AOL:
  • Outlook/MSN/Hotmail:
  • Yahoo:
  • Gmail:
  • Juno/Netzero/UnitedOnline:
  • RoadRunner:

If you have problems with other ISPs, please check their website for email guidelines.

STEP 2 of 4: Fix your basic infrastructure

Before you continue you should make sure to setup basic deliverability practices. Most ISP’s will be more eager to help if you follow their practices since they will understand you are trying your best:

  • Set up authentication. (Super important if you have problems with Yahoo!) Read more here.
  • Set up your own tracking domains (Will automatically include List-Unsubscribe). Read more here.
  • Set up an abuse@ and postmaster@ email address on each of the domains you are using as your sending address (And read emails coming to these addresses, otherwise you are).
  • Register with Read more here.

STEP 3 of 4: Prepare to contact the ISP

If you need to resolve a blocking problem, collect this information and have it at the ready before you contact an ISP:

  • About Your Business
    • Business name
    • Business address
    • CAN-SPAM compliant physical address used in e-mail campaigns


  • About Your Abuse Contact Person
    • Contact name
    • E-mail address
    • Phone number


  • About Your Mailing Domains
    • IP addresses and subnets (PTR records or pointer records that associate each IP address with a name, are required for all IPs)
    • Domain names
    • Domain keys records (required for Yahoo). You will find the DomainKeys txt record here.
    • SenderID records (In Symplify the SenderID record is: “v=spf1 ~all”)
    • Sender Policy Framework (SPF) records


  • About Your Privacy and Data Practices
    • Web site opt-in URL
    • Unsubscribe mechanism
    • Privacy policy URL

  • Where You Receive Feedback Loop (FBL) e-mails
    • When sending from Symplify your Feedback Loop address is:
    • Hotmail:
    • Yahoo!:
    • Comcast:
    • COX:
    • AOL:
    • BlueTie:
    • USA.NET:
    • Roadrunner:
    • OpenRS:
    • ALL OTHERS: and

STEP 4 of 4: Contacting the ISP

When you have prepared all the above we have a few tips when contacting the ISP:

​Explain yourself but don’t be defensive. Never say “We don’t spam” or “This wasn’t spam according to law”. This will never work here. If you did something wrong, admit it and fix it. This is better: “Our sales department apparently slipped in a prospects list from their CRM into that last campaign. I’ve punched the marketing director in the gut for not catching that. It won’t happen again. We have a good record until now so I hope you’ll consider delisting us.”

Don’t be discouraged if you send a long detailed email to the ISP and you only get an automated reply asking you to send “Email headers”. Your email does eventually make its way to someone but it might take several days for large ISPs and weeks, months or even never for private filtter companies like Postini and Barracuda.

The person who can unblock you is not someone who enjoy blocking you. It’s a normal person who gets gazillions of emails each day about: “I keep getting viagra emails. Help!” or “People say I’m sending Viagra emails but I’m not! Please fix the internet!”. Give him/her facts and evidence that you fixed the problem.


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