select one that had a link to a page in the site, and click Save as new...
send it again
The tracking links generated when the new copy is sent are broken. They contain the string newsletterlinks twice, e.g. http://example.com/newsletterlinksnewsletterlinks/hextrackinghashishere
(And for what its worth, removing one 'newsletterlinks' and attempting to visit the resulting URL does not succeed either, suggesting the hash is bogus.)
If you:
The tracking links generated when the new copy is sent are broken. They contain the string newsletterlinks twice, e.g.
http://example.com/newsletterlinksnewsletterlinks/hextrackinghashishere
(And for what its worth, removing one 'newsletterlinks' and attempting to visit the resulting URL does not succeed either, suggesting the hash is bogus.)