We are looking at our recipient activity reports and seeing that there are several email addresses that show as unrecognizable character strings. A couple of these addresses show a lot of email open and click activity and we would like to have some idea of who they are and what is going on. Your help is much appreciated.
The email addresses in the reports can show in an unreadable format when:
1) the recipient's email client breaks the tracking link so it appears in two lines. In most cases this happens if the recipient opens your message in the plain text format. In this case the last part of the link where the encoded recipient's email address appears on the second line. But the link is working. When a recipient clicks on it, the page opens well but the recipient's email address may not be registered correctly;
2) the tracking link which originally contained upper case and lower case letters appears in all lower case letters. This can be done by either the recipient's email client (some of old clients were known to do that), or script if you hit a spam trap email account. The script tries to parse the URL, investigate the domain it leads to and report it to the spam trap owner (anti-spam organization or ISP).