Does list cleaning guarantee acceptance by Mailchimp?

As many of my clients are aware, I provide Mailchimp subscriber email address verification and validation. With this service the subscribers that people want to import into Mailchimp are analysed one by one for errors or quality concerns. In many cases my customers have already received an Omnivore warning or their accounts have been suspended because of too many low quality email addresses being imported into a Mailchimp list. I then analyse each and every email address in the list and provide feedback as to the quality of each address and the reason for any quality issues (should there be quality issues). In addition I provide a list of email addresses that are more than likely to be accepted by Mailchimp.

There are almost always some email addresses that fail verification (low quality). This is usually no fault of the list owner but rather because either; subscribers to the list were attained more than six months prior to verification, the list was purchased or Mailchimp has already checked the list and flagged quality problems.

I received the email below form a potential client and thought I should share the message and my response.

Just imported 1673 contacts from Benchmark Email into Mailchimp.
The Omnivore warning means I can’t email my contacts.
Does the cleaning GUARANTEE that I will be able to email all of the 1673 contacts. If not I think I will have to go back to Benchmark Email.
Thank you in advance.
Cheers.
[Customer name]

Hi [Customer name],
Thanks for contacting us. There is no guarantee that all your contacts will be accepted by Mailchimp. Mailchimp Omnivore has been invoked as there are definitely problems with some of your subscribers.
We perform various tasks on lists such as testing that the email address really exists, testing if the email address is a ‘catch all’ email address and various other measures. We then provide a sub-list of email addresses that we have a high confidence will be accepted by Mailchimp. As noted, Mailchimp has identified issues with a higher than average proportion of your subscriber email addresses being of low quality hence the Omnivore warning; we therefore can’t guarantee acceptance of the full list where there are issues with some email addresses in your list.
Please let me know if you’d like to use our services where we can provide a sub-list of email addresses that Mailchimp are more than likely to accept.
Regards
Gary

If you’d like assistance with ensuring that your list of subscribers is valid and ready to be imported into Mailchimp the please let me know.