Open link from mail, changes the original url

[alicertel]

All the actions related getting url from email, somehow changes the original url.

Expected url : http://example.com/?email_id=566xy&... Returned url : http://example.com/?email_idV6xy&...

As you can see =56 replaced with the V. Hexedecimal 56 refers to V in ASCII Character, if that helps.