mail 4.4 urls link opens different website

hello,

we experience something very strange, in one of our emails we have included a url (syntax http://www.example.com) which opens a completely different website in safari, while showing the url included in the email.

we have tried the following:
1. emptied safari cache;
2. tried from different computers on various networks > same behaviour;
3. checked the raw source of the email > no reference to the other website anywhere;

needless to say the other website is available when simply typing the url in safari's address bar.

any ideas much appreciated.

ds.