Exchange 2010 – Maximum length of SMTP Address


A customer during a Lotus Notes to Exchange 2010 Migration discussion asked what is the maximum length for SMTP e-mail address in Exchange 2010. Well, better document it, so here it is…

The maximum length is 571 character, that includes the @, Domain Name & Name. A Sample Email Address looks like this, where.

Name part of the Email Address: 315 characters
Domain Part of the Email Address: 255 characters
and the sign (@)

So long…