Unable to send SMS using default Fortiguard SMS Messaging Service

It seems like this was a problem on the Fortinet side , issue seems to be resolved just got spammed with a bunch of test SMS in the backlog.

Even FortiGuard Message Centers do use actual telco providers to deliver messages. So possible bottleneck could be anywhere. On FortiGuard, on mobile service provider for your location, their infrastructure .. anywhere.

Need to note that SMS is usually service without delivery guarantee.

If you use those SMS for example for 2FA token codes delivery, then I would suggest to consider other options like physical tokens, mobile tokens or cloud based tokens. They even might be cheaper in long term then SMS messages.

Alternatively you can configure quite a variety of 3rd party SMS Gateways in FortiAuthenticator, so it can deliver "SMS" for example to defined SMTP .. and so you'll get your token to your email via your private email server, free of charge, for example.

But for 2FA I personally really like mobile/cloud tokens and PUSH notifications. Simple, fast solution and comfy to use.

My (subjective - I work at telco) opinion - if to use SMS at all, then use local to the sending device SMS GAteway/Provider/telco, not the one from the Fortinet. I see SMS via Fortiguard as a means of free trial/pilot for the SMS MFA, after which you should switch to more adjacent and reliable SMS provider.  In locations where I cannot get local SMS gateway and Fortitoken is not an option, I prefer to use email as MFA with increased timeout for reliability. 

thank you guys for answers. Are you services expensive?