I'm afraid I have no good news for you. Salamis Lines was the ONLY ferry running from Europe to Egypt, and then only seasonally. Recently they seem to have decided to avoid the whole area. At this time we know of no service across the Med to Egypt.
Your best bet is likely to drive around through Syria, Lebanon (optional) and Jordan, all of which have been recommended by travellers.
This topic is a popular one, if you Search (above right) on the words 'ferry' and 'Greece' you will find over 50 threads. Check this one out:
Good suggestion in there about leaving your vehicle in Jordan rather than taking it into Egypt, which is a major hassle.
Good luck and let us know how you go!
"It matters not what goal you seek
Its secret here reposes:
You've got to dig from week to week
To get Results or Roses."
'One world, two wheels'