SMS documentation

Traccar tested on kannel with opensmppbox. Used Huawei modem as transport. The benefit is you can route incoming SMS.
Not many SMS operators provide backward route and "routable" number or it costs a lot.

Also want to say, while testing I noticed that SMS do not give much benefits now in the age of Pushes.
Gmail push notification comes much faster to my mobile phone than SMS.

Gmail push notifications there are many daily ... but the TraccarSoundAlerts are wonderful ;-DD

https://github.com/tananaev/traccar/issues/3073#issuecomment-292228513

Have been using the following SMS provider and it has been working fine. Example config included below.

Provider:
http://www.i-digital-m.com/en/

Traccar config section:

        <entry key='sms.smpp.enable'>true</entry>
        <entry key='sms.smpp.host'>213.158.112.40</entry>
        <entry key='sms.smpp.port'>3342</entry>
        <entry key='sms.smpp.username'>[Your username @ i-digital-m]</entry>
        <entry key='sms.smpp.password'>[Your password @ i-digital-m]</entry>
        <entry key='sms.smpp.ton'>0</entry>
        <entry key='sms.smpp.npi'>0</entry>
        <entry key='sms.smpp.sourceAddress'>[Your service name, e.g. domain.com]</entry>

They allow a free account setup for testing. Worked for me without any issues. Make sure to allow TCP port 3342 to access the internet.

Where is the function to send sms, so that we can modify according to our need?

I have integrated clickatel sms gateway if any one wants you can ping me
kirancse123@gmail.com

Why not just post your solution online if it works?

What does this problem mean? Some help // SMPP configuration

Invalid Addresses - SendFailedException (... < NotificationMail:124 < NotificationResource:61 < ...)

Your error indicates incorrect email address.