Xpath
/control/message/send-date
Immediately
<send-date> <immediately></immediately> </send-date>
15 mins after the campaign are loaded on Mapp Engage
<send-date> <in>PT15M</in> </send-date>
Specific date, time format relative to GMT
<send-date> <date>2020-11-12T18:00:00+02:00</date> </send-date>
Send date with max delay parameter:
<send-date> <date max-delay-minutes="90">2018-06-30T18:00:00+02:00</date> </send-date>