Troubleshooting troubleshooting

Are you experiencing a deliverability problem? You may find the solution here.

Same error message for an ISP same-error-for-an-isp

Why do I always get the same error message for a particular ISP?

If you always get the same error message for an ISP, your email or IP may have been detected as faulty by the ISP. Carry out the following recommendations:

  • Check whether you receive a large percentage of failures linked to inexistent email addresses (User unknown failures).
  • Update your subscription forms to detect any errors in the domain names entered (for example: or
  • If you notice errors stating that your messages are declared as spam, or that your messages are constantly blocked, try excluding the recipients that have not opened or clicked in one of your messages in the last 12 months from the target.

If the problem persists, contact the commercial or deliverability services, or Adobe Campaign support.

Denylist versus quarantine denylist-versus-quarantine

  • What is the difference between an email address on denylist and a quarantined email address?

    • The status On denylist is a result of a feedback loop (when a person reports a message as spam).

    • The status Quarantined is a result of a soft or hard bounce.

    For more on this, see this section.

  • What do the different quarantine error reasons mean?

    Here are 10 possible reasons: not defined, user unknown, invalid domain, address on denylist, refused, error ignored, unreachable, account disabled, mailbox full, not connected.

    For more on this, see Understanding quarantine management.

Removing from denylist removing-from-denylist

  • One of my recipients was added to the denylist by mistake. How do I remove them from the denylist so that I can start sending them messages again?

    • Go to Administration > Channels > Quarantines > Addresses.
    • In the details of the corresponding record, set the value of the Status field to Valid.
    • Save the record.
  • How can I find out whether one of my IPs is on denylist? How do I remove my IP(s) from a denylist?

    To check whether your IP address is on denylist, you can use various web sites to verify it, such as:

    Generally, the result of the IP address check will return a list that contains details of the denylist and also the name of the web site that blocked the IP address.

    By clicking the corresponding link, you can access the web site details.

    Then, you can request that your web site be delisted from the web site that added the IP address to its denylist.

    note note
    The delisting process may vary depending on the web site. Some sites require you to create an account, while others just need you to provide the IP address.