As of September 13th, 2025, Iridium has discontinued its Iridium Mail App and related services.
You could consider PredictMail, together with a DataHub,
Further details can be found here, https://www.predictwind.com/predictmail
The DataHub is a feature rich device, apart from PredictMail it also offers automated GPS tracking with the potential of sharing your boat NMEA data to your GPS page etc. The DataHub can generate AI polars for your boat, offers over the horizon AIS and the Anchor Alert App. The last three features require a Professional forecast subscription.
PredictMail is a subscription-based service offering 3-month (US$59.95) and 12-month (US$119.95) plans. Your first subscription comes with an extra free month to give you time to set up and test the service in advance.