When you send an e-mail by a (DNS) auto-server, a direct connection is created between the computer and the server that has the recipient’s e-mail, to send the e-mail. In this way of sending the e-mail goes directly to the recipient. No SMTP provider is used.

Newsletter allows you to configure a SMTP Server, using an account you have in an access provider or in a hosting company. The sending by SMTP is more secure, faster and the fail index in the sending is lower than using an auto-server.

When you use a SMTP Server, the e-mails aren’t directly sent for the recipients but for the SMTP Server that, after, processes the sending of each e-mail. It can overload the Server and, because of this, many Internet providers have restrictions to use this service, for example, limiting in 100 e-mails the maximum quantity of sending per hour.

The sending of e-mails by the (DNS) auto-server is a way to escape of the restrictions and limitations of sending, generally, imposed by the access provider. As the e-mails are sent directly by your machine, you can send any quantity without have the limitations like when you use your SMTP server. The disadvantage in sending e-mails by an auto-server is becausemany providers have restrictions relatives to the receiving of not authenticated e-mails (sent by an auto-server) and, because of this, many e-mails that are available don’t be able to be sent. It isn’t a Newsletter fail, but a problem relatives the politician about e-mails that diversify between each access provider and hosting company.

The restrictions of e-mails reception sent by an auto-server more common are:

• Don't accept the e-mails;
• Accept a limited amount of e-mails sent by a same remittent;
• Don't accept e-mails in certain times of the day or in special situations (like when the server is overloaded).

Normally, the available e-mails sent by an auto-server are processed. If you have problems with this form of sending, the only form to solve it is getting availability of sending in a SMTP server. It can be made with any agreement or contract with the access provider or hosting company , or by a contract with dedicated server.