My DNS, MX, domain etc is all set up and working properly and email works.  I want to redirect one email address on my domain to a non Zoho destination.  This is normally easy to do at the DNS / Nameserver level but because Zoho is not running my nameservers I can't do it at in DNS.

I have one user but four valid addresses at my domain.  Catch-all is disabled.  There's 

me@mydomain. com - zoho account name

name2@mydomain. com      -  goes to me@mydomain. com

name3@mydomain. com      -  goes to me@mydomain. com

externalname@mydomain. com    -  needs to go to externalgmailname@gmail. com 

I have looked at

1 mailbox alias - can't specify an external domain

2 policy - can't specify an external domain

3 email forward - only applies to a zoho account name email

4 filter to forward - sort of works but is not appropriate as it routes mail for externalname through the me@mydomain account and makes it visible

5 split delivery - only works for mydomain addresses, can't translate to a gmail address

Is there something else that I have missed ?

Thanks

Mark