Emails from custom SMTP were failed

buongiorno, volevo sapere come mai quando i miei clienti effettuano una prenotazione, non ricevono una riposta (sia che io abbia accettato sia che io abbia negato)

Hi campingisola,

Thanks for reaching out to Jotform Support. I’d like to let you know that I’m using a translation tool to provide assistance, but if you would prefer to get assistance in the Italian language, we can forward your ticket to our Italian team. But, please note that it could take longer to receive a response.

Now, I'll help you with your question. When I checked the email logs, it seems that all failed email entries, were from your custom address. It could be that your custom SMTP is misconfigured or your email provider prevents your custom sender address because of some reason. Can you please try setting up your Sender Email again? If you're using Gmail, let me show you how to set that up:

• Click here to sign into your Google account and access the App Password Generator.
• In the list of available apps, click on Mail.
• In the device list, click on Other.
• Enter your Custom Name, such as Jotform.

• Click on the Generate button.
• *Copy and save the password to your computer.
• Finally, click the Done button.

*It is very important that you save the password to your computer so you can use it again later. If you don't save it, you'll have to generate a new one again, because Google doesn't let users view their passwords after they click the Done button.

Now, to add the Sender email:

• Go to your My Account page, and click on Settings, or visit here directly.
• Click on the Add Sender Email button.

• Enter the following information:
• Email Address: {your email address}
• Hostname: smtp.gmail.com
• Port: 587
• Username: {your Gmail address}
• Password: {your Gmail or app-specific password}
• Security Protocol: TLS

• When you're finished, click on the Send Test Email button to make sure that everything is working. If it works, click on the Add Email button. If not, please check the details again and correct any errors.

You might also want to check out this guide about How to Use Your Gmail Account as Your Email Sender via SMTP. 

Give it a try and let us know if you need any help.