Wishing you many happy returns of the wedding day．
正值阁下新婚之禧，恭贺幸福无量。

My heart felt congratulations on your coming happy union!
谨向你们即将到来的幸福结合致以衷心的祝贺。

My sincere congratulations on this auspicious event of yours．
值你俩大喜之日，谨致最诚挚的；况贺。

Our best wishes to the two of you for a happy marriage filled with all the good things．
(我们)愿你俩婚姻美满幸福。

Best wishes from one of your old friends on your engagement.
在你们订婚之际，请接受一个老朋友最美好的祝愿。

My very best wishes to you for a lifetime of happiness．
向你俩致以最美好的祝愿，祝你们终生幸福。

I take great pleasure in sending here with a little wedding present in celebration Of the happy event．
喜送小小礼品一份，庆贺这一大喜大吉之事。