Disabling emails in Debug Mode Aspnetzero

I had this issue and just assumed the code was there for looks but didnt actually work (Meaning the only thing it did was show "test email sent" but no backend code did anything)

After maliming's comment I realized it wasnt just me.

I started checking what the log said as he mentioned and log mentioned:

INFO  [35   ] pNetCore.Cors.Infrastructure.CorsService - CORS policy execution successful.       
INFO  [35   ] uthentication.JwtBearer.JwtBearerHandler - Successfully validated the token.
INFO  [35   ] ft.AspNetCore.Routing.EndpointMiddleware - Executing endpoint 'companyName.Configuration.Host.HostSettingsAppService.SendTestEmail (companyName.Application)'
INFO  [35   ] c.Infrastructure.ControllerActionInvoker - Route matched with {area = "app", action = "SendTestEmail", controller = "HostSettings"}. Executing controller action with signature System.Threading.Tasks.Task SendTestEmail(companyName.Configuration.Host.Dto.SendTestEmailInput) on controller companyName.Configuration.Host.HostSettingsAppService (companyName.Application).
WARN  [35   ] Abp.Net.Mail.NullEmailSender             - USING NullEmailSender!
DEBUG [35   ] Abp.Net.Mail.NullEmailSender             - SendEmailAsync:
DEBUG [35   ] Abp.Net.Mail.NullEmailSender             - admin@aspnetzero.com
DEBUG [35   ] Abp.Net.Mail.NullEmailSender             - 
DEBUG [35   ] Abp.Net.Mail.NullEmailSender             - companyName test email
DEBUG [35   ] Abp.Net.Mail.NullEmailSender             - This is a test email.
INFO  [32   ] .Mvc.Infrastructure.ObjectResultExecutor - Executing ObjectResult, writing value of type 'Abp.Web.Models.AjaxResponse'.
INFO  [32   ] c.Infrastructure.ControllerActionInvoker - Executed action companyName.Configuration.Host.HostSettingsAppService.SendTestEmail (companyName.Application) in 27.1706ms
INFO  [32   ] ft.AspNetCore.Routing.EndpointMiddleware - Executed endpoint 'companyName.Configuration.Host.HostSettingsAppService.SendTestEmail (companyName.Application)'
INFO  [32   ] Microsoft.AspNetCore.Hosting.Diagnostics - Request finished in 51.2509ms 200 application/json; charset=utf-8

"USING NullEmailSender!" caught my eye and when I went searching the source, I came across this that solved my issue:

if (DebugHelper.IsDebug)
    {
        //Disabling email sending in debug mode
        Configuration.ReplaceService<IEmailSender, NullEmailSender>(DependencyLifeStyle.Transient);
    }

Edit: One additional intersting thing I noticed - You have to Save All in order to get the credentials to update, so after you input your SMTP credentials, Save All, THEN send test email - otherwise it tries to use the 127.0.0.0 credentials it originally has