Anyone can help me out? Many thanks!!

My parents need to renew their visa this year. They need a invitation letter from me. Can I email to them? Or I have to mail the letter to them?

可以发pdf, 让他们打印~

可以发pdf, 让他们打印~
Arlindgenono 发表于 7/18/2014 12:55:46 AM [url=http://forums.huaren.us/showtopic.aspx?topicid=1657046&postid=63695305#63695305][/url]

Thanks a lot! Then how should I sign the letter?