gustr.com is part of a free disposable email address service called Email Temporal Gratis. This service allows anyone to create a temporary email address that is only capable of receiving email. No legitimate email will ever be sent from gustr.com.
We do not provide a way for our visitors to send email from their gustr.com email address. Additionally, gustr.com has an SPF record that tells receiving mail servers to reject any emails that appear to come from a gustr.com email address. If you receive an email from gustr.com then you can be 100% confident that the email address was forged.
Email works a lot like postal mail: a person can write anything they want as the return address. For example, you could put a California return address on a letter and mail it to a friend from anywhere, such as New York or China. You could also put your friend's name and address for the return address and mail it from anywhere, even without your friend's knowledge. Email works just like that: anyone can put anything for the return address.
So how do you now where an email really came from? This is a tricky problem, but people normally rely on the email headers to find what server the email came from. This is similar to checking the postmark on a letter you send through the postal mail. It tells you where it physically originated from, but doesn't tell you who sent it. For a letter you receive in the mail you might know where mail should come from for a particular sender. For example, if your friend lives in California but you receive a letter from New York, you may think the letter is a fake. Email works the same way. The email domain name has a method of telling a receiving mail server where emails should be sent from, and if an email is received from somewhere else, it should be rejected.
Unfortunately, some mail servers (or their administrators) are unaware of this capability, and do not have this functionality turned on. If you receive spam (or any other emails) that appear to be from gustr.com, check to make sure your receiving mail server is honoring SPF records.
This is an easy one: just go to Email Temporal Gratis! You can instantly get a working email address that is only capable of receiving email. We never charge for this service and you can use it as much as you'd like.