Is possible to use electrum to send an Omni transaction but not an easy task since the transaction, and the associated Omni information, must be created manually.
Here is how to perform an Omni transaction with Electrum (in this case a Tether transaction).
The OP_RETURN data for a Maidsafecoin transaction are:
6f6d6e69000000000000000300000000XXXXXXXX
The XXXXXXXX is the amount of Maidsafecoin to be transferred (in hexadecimal).
For example 0000000A for a transfer of 10 Maids.
Of course, use this information at your own risk.