Refer to Figure $2-$ An Email System.

$($i$)$ Identify each of the Client$-$Server components labelled XXXX and YYYY and

the Client component marked ZZZZ$.$

$(6$ marks$)$

$($ii$)$ Explain the role of each of the following components: XXXX Client$/$Server$,$

YYYY Client$/$Server and User Agent.

$(9$ marks$)$

$($iii$)$ Identify the protocols used by the XXXX and YYYY Client$/$Server components

and the ZZZZ Client component and, identify which would be associated with

the following interaction:

HELO localhost

MAIL FROM:

joe.bloggs@google.com

RCPT TO:

mary.jane@tudublin.ie

DATA

$(10$ marks$)$

Figure $2$: An Email System.