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Have you thought about buying a cheap cell phone with a plan? You can turn an Android phone into an SMS gateway.

kevincox 5y ago
Although finding a carrier that is ok with this type of use is more difficult. Most have fairly low rate limits and will consider kicking you off the network.
Andrew_nenakhov 5y ago
Won't work in practice. We tried that, and (scum)phone companies apply arbitrary filters to SMS sent with 'unlimited plans', not delivering messages which they don't like. Experiments have shown that SMSs with random text arrive in 80-90% of cases, but if they contain words like 'verification', 'code', 'код', еtc, only about 10% do reach the recipients. Of course, these same operators offer commercial rates for delivering 'branded' messages at a far higher rates.
- sofixa 5y ago
  Have you tried cheating their regexes with mixing Cyrillic and Latin script? E.g. кoд ( the o is Latin, the rest Cyrillic). It's the same letter visually but a different character. Even Google Translate used to trip up with this. PS: funny, HN bolds Cyrillic characters
  - Andrew_nenakhov 5y ago
    Mixing helps bypass the screen, and simply sending the numbers helped. But still, we decided to ditch this number verification thing via SMS altogether and start torturing users by missed calls.
- twunde 5y ago
  The reason this doesn't work is because of the pressure phone carriers have gotten about reducing the amount of spam phone calls and SMS (from Congress, state governments and regulatory bodies like the FCC). These arbitrary filters on consumer level plans are typically about blocking spam from spoofed numbers and non-compliant businesses. If you think about it, its EXACTLY how email works today. You _can_ try to send millions of emails per a second from your gmail account, but a) your emails will likely be caught by spam filters due to the high volume and b)gmail will notice suspicious activity and shut your account down.

Although finding a carrier that is ok with this type of use is more difficult. Most have fairly low rate limits and will consider kicking you off the network.

Andrew_nenakhov 5y ago

Won't work in practice. We tried that, and (scum)phone companies apply arbitrary filters to SMS sent with 'unlimited plans', not delivering messages which they don't like. Experiments have shown that SMSs with random text arrive in 80-90% of cases, but if they contain words like 'verification', 'code', 'код', еtc, only about 10% do reach the recipients. Of course, these same operators offer commercial rates for delivering 'branded' messages at a far higher rates.

sofixa 5y ago
Have you tried cheating their regexes with mixing Cyrillic and Latin script? E.g. кoд ( the o is Latin, the rest Cyrillic). It's the same letter visually but a different character. Even Google Translate used to trip up with this. PS: funny, HN bolds Cyrillic characters
- Andrew_nenakhov 5y ago
  Mixing helps bypass the screen, and simply sending the numbers helped. But still, we decided to ditch this number verification thing via SMS altogether and start torturing users by missed calls.
twunde 5y ago
The reason this doesn't work is because of the pressure phone carriers have gotten about reducing the amount of spam phone calls and SMS (from Congress, state governments and regulatory bodies like the FCC). These arbitrary filters on consumer level plans are typically about blocking spam from spoofed numbers and non-compliant businesses. If you think about it, its EXACTLY how email works today. You _can_ try to send millions of emails per a second from your gmail account, but a) your emails will likely be caught by spam filters due to the high volume and b)gmail will notice suspicious activity and shut your account down.