If your campaign can send emails but the links (hyperlinks) in the email/s lead to an error page, most likely the problem is with your sender domain's DNS. 


First, try to check your domain nameservers by going to DNSChecker.org. Paste your sending domain on the field on the left side of the page, upper part. Then select "NS" from the dropdown menu beside the field. 


Click the Search button and see the results below. If the results don't show your hosting's domain name with a "servers" extension (i.e. "namecheap.com/....servers", "godaddy.com/...servers"), then something is wrong with your DNS. You'll need to have your domain DNS setup checked by your hosting support.


If the results show your domain name with the "servers" extension but your email links are still going to an error page, please try to reach out to MLA Support and let them know about the problem.