2.2.2 IMAP4 Delegate Access Extension Messages

The IMAP4 delegate access extension extends the LOGIN command, as specified in [RFC3501] section 6.2.3. Specifically, it extends the user name argument of the LOGIN command so that a delegate and a delegator can be specified in the login string. This extension only affects the arguments of the LOGIN command and does not change the specification of the LOGIN command in [RFC3501].

There are four formats for the user name argument when using delegate access with IMAP4. The message syntax for the four formats is shown in ABNF.

 domain                       = 1*VCHAR  ; The name of the user's domain
 delegateuseralias            = 1*VCHAR  ; The delegate's e-mail alias
 delegateuserupn              = 1*VCHAR  ; The delegate's UPN
 principaluseralias           = 1*VCHAR  ; The principal's e-mail alias
 principaluserupn             = 1*VCHAR  ; The principal's UPN
 password                     = 1*VCHAR  ; The delegate's password
  
 delegate_spec                = (domain "/" delegateuseralias) / delegateuserupn
 principal_spec               = principaluseralias / principaluserupn 
 IMAP4_DELEGATE_LOGIN_Command = "LOGIN" SP delegate_spec "/" principal_spec SP password

The "domain" part of the login string represents the delegate's domain.

The "delegateuserupn" part of the login string represents the user principal name (UPN) of the delegate, which is composed of the user's identifier and domain, as specified in [RFC822] section 6.1.

The "delegateuseralias" part of the login string represents the e-mail alias of the delegate.

The "principaluserupn" part of the login string represents the UPN of the primary account, which is composed of the primary account's identifier and domain, as specified in [RFC822] section 6.1.

The "principaluseralias" part of the login string represents the e-mail alias of the primary account.