Every day with every contact: There was an issue sending your email
Hello @Qforma , Thank you for the extra information, based on your subscription level, we will need to continue our conversation in the Community, but I will help with this case, did the example contact have any bounce message or it was previously bounced?
Could you please send me a DM with the example contact email and a HAR file capture when the error occurs. ( step by step here)
With 1:1 emails sent through a record, they are technically sent by your email server, so there might have been a temporary issue at that moment in time when sending that email to your server.
Also, a built-up browser cache can sometimes cause that error, so it's possible that it was a temporary browser issue. Clearing your cache can help.
Did you try to re-send and continually get hit with the same error? Wanted to share this knowledge base here with more information.