1
WP Mail SMTP Paid version Pro
Network-wide settings and central subsite logs are Pro; Lite can be set up per subsite.
96feature score
WordPress SMTP & Email Delivery Plugins with Multisite support
Network-wide or per-site settings on multisite. 4 of the 8 plugins we track include it.
2
Easy WP SMTP Paid version Basic
Network-wide settings and central logs/reports are Pro; subsites can be set up individually.
97feature score
3
FluentSMTP Partial
Works on multisite but is configured per subsite, with no network-wide settings.
89feature score
4
Post SMTP Included
Multisite supported with global network settings in the free plugin.
90feature score