Melilla sits outside the EU customs and VAT territory: every shipment clears customs despite being Spanish territory.
Melilla shares Ceuta's regime: Spanish territory, but outside the EU customs territory and outside the VAT territory. Every movement to the mainland is documented as an export and an import, with the declarations and settlement that implies.
What sets it apart is the sea distance. The link is not with Algeciras but with Málaga, Almería or Motril, and the crossing runs to several hours rather than one. On top of a fixed-schedule departure, that makes the choice of sailing the heaviest factor in the date.
We have no loads of our own here either, and we will not pretend otherwise. What this page offers is the customs and logistics framework, which is what we can state with certainty.
Is it the same regime as Ceuta?
Yes on customs and tax: both autonomous cities sit outside the EU customs and VAT territory. The difference is the sea: from Melilla the crossing to the mainland is appreciably longer than the Ceuta–Algeciras hop.
Can you transport from Melilla?
We have no mileage from this origin, so we look at each job on its own and tell you frankly what lead time we can hold before you commit the freight. We would rather do that than take it on and learn as we go.