Some ISPs require that you use an email address they have issued as sending before you can use their SMTP server. See our instructional video and contact your Internet service provider to ascertain their possible. requirements as well as their SMTP address, SMTP port.
Some mail systems does not support using the same sender and reciever mail address. It is recommended to use different sender and reciever mail.
when using gmail, make sure that less secure apps are allowed. Less secure apps, are apps from developers not known by gmail. This does not mean that the SafeHom app is not secure.