add input for insert multiple smtps in the same time + fix from

[ymsoufiane]

This pull request introduces the ability to add multiple SMTP configurations simultaneously through a new input field. Additionally, it addresses a critical bug where the 'From' address was always set to a default value. This behavior caused errors when sending emails using multiple SMTP servers. Now, the 'From' address is correctly taken from the custom headers defined in the configuration for each SMTP entry, ensuring the correct sender information is used for each email sent.