Dear Sir/Mandam ,
How are you?
We came across your website on google and would very much like to exchange links with you or establish a long-term relationship with your site .
Swapping with similar themed and good quality website can help improve search engine position and encourage mutual visitors to each website .
So I 'am writing email to you to see whether we can have this chance to cooperation with your site.
Please send us your own detailes and we would be delighted to add a link to our website.
Many thanks for your time and we look forward to hearing from you .