People send e-mail for all sorts of reasons. Etiquette is dictated by the audience and reason for the correspondence. Business e-mail messages should have a more professional tone than a personal, friendly e-mail to family members.
Using proper etiquette on the Internet, including in e-mails, is called "Netiquette".
so people can look up barney
It is acceptable, but ask for an RSVP so you know it was received.
No, it is not proper etiquette to send weddinginvitations by email if it is a large wedding. If you are having a small wedding and it's casual then you could send a card invitation by email.
Etiquette for email is most often referred to as netiquette.
Business email etiquette is a professional manner when contacting a colleague through email. To achieve good email etiquette follow a few steps. These steps include avoiding slang or rambling, address the recipient by name, label the email with a professional subject line, and write the purpose of the email out clearly.
* It's appropriate, but a nice Thank You card signed by you (perhaps a note inside) is the proper etiquette.
Business email etiquette is a professional manner when contacting a colleague through email. To achieve good email etiquette follow a few steps. These steps include avoiding slang or rambling, address the recipient by name, label the email with a professional subject line, and write the purpose of the email out clearly.
Be yourself
Please practice proper etiquette when in public.
Netiquette
Yes. It is proper etiquette, although it is also common for them to decline (but that probably depends on your relationship with him/her).