When sending internationally, filtering takes place by the local network - not only on your message content but also who your message appears from to the recipient.
In reality, sending internationally will need frequent monitoring, as filters can change per network per country daily (without always being disclosed).
Some countries provide an option to pre-register your brand or purchase an approved number with the networks to reduce messages being filtered. It’s worth noting this does not guarantee messages will not be filtered - but it does add an element of whitelisting.
We have put together some guidance on the level of known filtering and any options to whitelist, all in a handy filtering guide - Drop us an email at firstname.lastname@example.org for a copy.
NOTE: Please ensure that the rules and regulations for sending to your desired country are fulfilled before you send.