How to whitelist specific VPS to allow SMTP traffic if option "Disable SMTP traffic" is active

Question

How to whitelist specific VPS to allow SMTP traffic if option "Disable SMTP traffic" is active?

Answer

There's no out-of-the-box functionality yet, therefore vote for the corresponding feature suggestion and status monitoring. Popular suggestions are likely to be developed.

As a workaround, a VM can be whitelisted manually:

SMTP restrictions are applied for each VM in /usr/local/solus/ovs/{UUID}/rules

For example, SMTP rules are following:

# cat /usr/local/solus/ovs/{UUID}rules
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp tcp_dst=25 action=drop"
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp tcp_dst=465 action=drop"
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp tcp_dst=587 action=drop"
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp6 tcp_dst=25 action=drop"
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp6 tcp_dst=465 action=drop"
ovs-ofctl add-flow br-routed "in_port=sol-279 priority=37000 tcp6 tcp_dst=587 action=drop"

In case you don't want them to be applied for some VMs, you can remove them from the file.

Note, that the rules file is automatically emptied if there're changes in SolusVM 2 UI > Settings > Network rules