I have a need to create a single mailbox with a large number of alias email addresses. I cannot find documentation on the maximum number of SMTP addresses that can be associated with a single user. Can someone point me in the right direction. Many thanks in advance!

David

Each mailbox can have up to 1200 addresses (As of Windows 2003, can't find a more recent number). 

http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_28381169.html

Hi David,

I've never heard of any restrictions about this, however, base on my search, I find a similar thread mentioned this question for your reference:

https://social.technet.microsoft.com/Forums/office/en-US/2c167213-731d-439f-855e-2dcb1ffd1d31/maximum-number-of-email-addresses-per-user-exchange-2010-sp1?forum=exchangesvradminlegacy

One member said:

I could see one account with 1203 SMTP addresses. I cannot add more addresses, I get an error message when I try to add more. Maybe it is the limit. Im still researching to be sure if it is a limit or not.The exchange is 2007.

Best regards,