https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59830#M13414 Actually, now I got it working sending mail from an address starting with ""0"". But it's still failing to reply to a mail sent from address starting with number 2, e.g. 240example@example.com. Thu, 25 Jan 2018 19:29:00 GMT rahlman 2018-01-25T19:29:00Z https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59829#M13413 I'm using the MAPIEx "Reply To Mail" action trying to reply to a sender who's e-mail address begins with a number, more specifically "0". For example "024example@example.com" Calling the Reply action fails and I get a message "Failure in Reply To Mail function of Blue Prism Extended MAPI Automation. Failed to add TO recipient:" I'm able to reply to mails from "normal" addresses that do not begin with a number (e.g. example@example.com). So it seems that this type of mail address beginning with the number 0 is the problem. Has anybody else had this issue and how did you solve it? Thu, 25 Jan 2018 17:16:00 GMT https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59829#M13413 rahlman 2018-01-25T17:16:00Z https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59830#M13414 Actually, now I got it working sending mail from an address starting with ""0"". But it's still failing to reply to a mail sent from address starting with number 2, e.g. 240example@example.com. Thu, 25 Jan 2018 19:29:00 GMT https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59830#M13414 rahlman 2018-01-25T19:29:00Z https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59831#M13415 Got this fixed by modifying the MAPIEx's page ""Reply To Mail"", Code stage ""ReplyToMail"", row 29: reply.AddRecipients(RecipientType.TO, msg.SenderEncoded) => reply.AddRecipients(RecipientType.TO, msg.SenderEmail) Hope that helps if somebody has a similar issue. Thu, 25 Jan 2018 20:19:00 GMT https://community.blueprism.com/t5/Product-Forum/MAPIEx-Failed-to-reply-to-an-email-address-beginning-with-a/m-p/59831#M13415 rahlman 2018-01-25T20:19:00Z