The SMS sending / receiving function is abnormal.

I tried sending and receiving from inreach via the Iridium satellite with inreach address, email, and SMS, but I couldn't do anything other than inreach address and email.

Even if I send SMS, the other party does not receive it at all and there is no transmission error. By the way, it is in Japan.

How about everyone?

The problem is almost certainly with the local (to the recipient) SMS gateway, or with the recipient's cell network. Check the Inbox on your account at explore.garmin.com. You should see the outbound SMS messages there. That indicates that the messages made it as far as the Garmin servers.

From the Garmin servers, the messages are forwarded via Internet to an SMS gateway in the general vicinity of the recipient's "home" cell provider. The gateway forwards the message to the cell provider. The cell provider delivers it to the phone.

If the messages made it to your inbox, there are several reasons why they might not be delivered:

1) The phone number does not have the correct country code. I believe this is 81 for Japan. Every SMS number used with an iR device must include the country code.

2) There is no gateway for the target region. This is unlikely. But since Garmin uses third-party gateways, it is possible.

3) The cell provider is suppressing the message. By default, SMS messages include a shortened link to web page map which shows the location from which the message was sent. Some cell phone providers suppress messages which include short links - the provider assumes it is spam. You can remove this link. See the SMS Message Configuration in the lower right corner of the Account tab at explore.garmin.com. Be sure the box for "Include a link to an online map..." is NOT checked.

So you can control (1) and (3). If you are sure that neither of those is the problem, open a support ticket.

Open a ticket with your local support organization.