In case you are still needing this (and to document another workaround) I had to find a way around this as well and I did not have any access to mess with the user accounts.
What I did was to use this form for the user name - uName@domain.com this worked. See example Below
PS C:\Program Files\VMware\VMware OVF Tool> .\ovftool.exe --X:logFile=deploy.log --X:logLevel=verbose --disableVerification --noSSLVerify -ds=dataStore -n=vmName C:\packer-vmware-iso.ovf vi://<IPAddress>/DataCenter/host/esxhost.domain.com
Opening OVF source: C:\packer-vmware-iso.ovf
The manifest validates
Enter login information for target vi://<IPAddress>/
Username: uName@domain.com
Password: ***********
Opening VI target: vi://uName%40domain.com@<IPAddress>:443/DataCenter/host/esxhost.domain.com
Deploying to VI: vi://uName%40domain.com@<IPAddress>:443/DataCenter/host/esxhost.domain.com
Transfer Completed
Completed successfully
Note the '%40' chars in the lines following the authentication. This led me to realize that the '@' char in the user name needed to be encoded. Then I could pass the user name and pwd in the command like this:
PS C:\Program Files\VMware\VMware OVF Tool> .\ovftool.exe --X:logFile=deploy.log --X:logLevel=verbose --disableVerification --noSSLVerify -ds=dataStore -n=vmName C:\packer-vmware-iso.ovf vi://uName%40domain.com:PWD<IPAddress>/DataCenter/host/esxhost.domain.com
BOOM. This worked. Finally.