Alphanumeric Sender IDs are supported. Numeric Sender IDs will be changed to randomized numeric Sender IDs or "SMS" as a generic Sender ID to ensure delivery.
Sender ID with operators name are restricted: KDDI, Softbank, NTT, Rakuten Mobile. Any Sender ID starts with UQ (including Uq, uQ, and uq) are restricted towards KDDI.
Gambling related content are not supported towards Japan all networks. Messages classified as illegal by the local networks are either discarded completely or the part of the illegal content will be removed.
Japanese characters unicode SMS are supported, and for other languages it depends on the handsets.
Concatenated messages are supported to all networks.
Other Features or Restrictions
Network level delivery receipts are supported.
For more information, see the following articles: