Email not delivered because of "550 spamcop" email suspended cause

[ColleenODay]

A member has reported recently not recieving our emails. Upon looking into the users activity log, I saw this message as of last week:

550 spamcop.mimecast.org Blocked - see https://www.spamcop.net/bl.shtml?199.15.213.53. - https://community.mimecast.com/docs/DOC-1369#550 [TY4iEaFyORqMurZxr7nvrg.us277]

The user has stated they have followed whitelisteing instructions. Any other ideas on how we can solve this deliverability challenge?

[loganlloyd100]

Hi Colleen - I took your IP address and ran it through MXtoolbox's blacklist checker. 

https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3a199.15.213.53&run=toolpage

You're actually listed on three blacklists. In my experience, this is a reflection of sending practices that result in high spam complaint rates. My recommendation is to review your email reports across all emails over the past six months and identify which emails drive the highest unsubscribe rates, which can act as a proxy for high spam complaint rates.

I would consider anything above .5% worth review but that's subjective to how much that campaign contributed to your overall send volume.

Additionally, excessive issues with delivering to invalid email addresses can trigger blacklisting. If you have leads/contacts who are highly inactive (no email opens/form fillouts/website visits in past six months) and they were created more than a year ago, they may pose a risk of becoming an invalid email address.

Finally, you can review Spamcop's website for how to avoid landing on their list and for how to be removed.

https://www.spamcop.net/reported.shtml

Rinse and repeat that for the other two blacklists you're on (0Spam, s5h.net).

[SanfordWhiteman]

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You're actually listed on three blacklists

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Kind of. This is a shared Marketo IP, though. (As with all Marketo instances by default.)

So there’s not necessarily any connection to @ColleenODay’s activity. Any instance using that IP is impacting its reputation. And while anyone can request delisting, if the offender is elsewhere that will only help temporarily.

But yes, standard practice is to review not only bounces in aggregate but detailed bounce reasons. Note Mimecast is the strictest of the major antispam services, and afaik an end user can’t bypass any Mimecast checks; only the admin of the Mimecast account can make this happen. Whitelisting shared IPs is also not something we advise, as it means you’re asking the recipient to potentially allow spam from those IPs.