As of November 25th, all emails with a security code are prioritized to go through your account's own SMTP settings, if those settings exist and are valid. NOT through Mobsted's centralized email gateway.
Earlier SMTP was only used for triggered email messages, not for system messages.
Another way to use your own email settings instead of centralized is to add a Mailgun.com account to your Mobsted account settings.
NOTE that if the SMTP password is filled the first attempt is sent using SMTP. If the SMTP attempt fails, then Mobsted will attempt to use your Mailgun account. A highly requested function of our Constructor! However, we did take some time to understand how to make it right for most use cases scenarios that we hear from our clients.
WAS
The issue was that every time you press Save in Constructor - our system deploys changes into the screen and every user who has that screen available in his app will immediately see those changes. This instant "Save" is Fast and easy during app's development, BUT bring lots of extra work for AFTER apps were released. Most users duplicated screens that needed changes, tested updated functionality of their apps on those screens and then either manually updated the original screen, or choose to change links all over their app to link to a new screen. Each of those was cumbersome and error-prone.
NOW
As of December 30th a new flexible deploy system is released to all accounts.
A more detailed description of this mechanism is located in How to Section of this help Docs
As usual - Looking forward to your questions and comments in the Support channels.