Is this not handled by the features introduced in Sage CRM 2020 R1?  (+) Sage CRM 2020 R1: Duplicate email detection - Sage CRM Hints, Tips and Tricks - Sage CRM - Sage City Community

HI, I'm afraid not as this is still reporting duplicates and expects you to resolve by ensuring a duplicate email address does not exist on the people within the group.
There are legitimate reasons why 2 contacts may have accounts@ as their email address and based on the data held against them both be included into a CRM group. This group cannot then be 'Sent to Mailchimp' as it reports duplicates BUT if you export to csv and then import that into Mailchimp via the Mailchimp import the second occurrence of an email address is dealt with, so all OK.
Is it a case of the Mailchimp API not supporting the same import functions that their 'import' process does and is therefore a Mailchimp limitation?

Hi there RBC_1, 

Did this get resolved for you? We are operating off CRM 2022 R1 and have the same problem?

Thanks,

Paul

Hi Paul

No, still an issue and even though logged directly with Sage support, no clear response apart from avoiding using the same email address against contacts.. But lots of people do share email addresses in certain departments or smaller organisations..

I'll chase to see if I can get an answer as talking directly with them later this week.

Roger

Hi Roger, 

Really appreciate the quick reply. 

Yes, we have a similar issue. We'd have multiple contacts within the same company but if we create a group in CRM with the person's email address, the Send to MailChimp button disappears. 

Hope the chat with them later in the week goes well and thanks again,

Paul