How mount (cifs) in Ubuntu a MacOS directory with all permissions

On the MacOS Samba server, you'll need to ensure the connecting account has "Full Read/Write" permissions to the shared directory. From there, this connection string will work for a manual mount situation:

sudo mount -t cifs -o uid=omicron,username=omicron,password=superSecretPassword!123 //192.168.1.X/directorynameshared /mnt/192.168.1.X/directoryname

Note that the uid and username values are both the literal name of the account on the MacOS machine, and the password value is also explicitly provided. I've not encountered a situation with a MacOS Samba host where the rw or gid flags are required when manually mounting a share.

If you plan on adding the mount to your /etc/fstab file, there are a few extra things you'll need:

//192.168.1.X/directorynameshared       /mnt/192.168.1.X/directoryname  cifs uid=505,gid=507,username=omicron,password=superSecretPassword!123,file_mode=0770,dir_mode=0770,nounix 0 0

Note that when the share is mounted via /etc/fstab, the uid and gid values are required, as well as flags for file_mode and dir_mode, plus nounix. The nounix flag is particularly important if your Ubuntu Server is going to be writing files via Apache and other service utilities.