How to add a non-standard address to a mailing list on MailChimp?

Question

Email Marketing

Good afternoon. There is a need to send a letter to only one person. For this, I preferred MailChimp. I prepared an HTML template, sent it to my gmail for verification, everything was great. Now I decided to send it to the same person who has an e-mail in the format:
[email protected] When trying to add this address to the list of subscribers, it displays the error The username portion of the email address is invalid (the portion before the @: name).
Tell me how to deal with this, or maybe there is some other, less capricious service?
Thanks in advance

Answer 1

There was a Cyrillic character in the address.... I'll ask the moderators to close the question.