SortByDomain is a procedure used to sort the Items in the email address collection alphabetically by the Domain name for the email address collection items. 

After calling SortByDomain, reading Items by their ordinal position returns the collection items in the alphabetically-sorted order. 

Use GetDomains to gather a unique list of Domain values found in the Items for the collection. 

Use AddressesByDomain to gather a list of collection items that match a specified Domain value.

Items 

GetDomains 

GetAddressesByDomain