How can external access to the Sendio ESP web interface coexist with OWA?
If Microsoft Exchange OWA (Outlook Web Access) is in use, the firewall is usually configured to forward inbound HTTP and/or HTTPS connections (port TCP 80 and TCP 443, respectively) to a specific public IP address to the internal server that is running the OWA component. In such a case, one of the following must be […]
What if I have a “catch-all” e-mail account for my domain?
By default, the Sendio ESP will reject inbound email addressed to unknown recipients. It is possible to override this setting although doing so is liable to open up a “floodgate” of spam arriving at the internal mail server. The setting is under the System | Inbound Control tab and is labeled “Unknown Recipient Address” (set […]
Must all sender addresses of outbound e-mail be real e-mail addresses?
If your company uses e-mail address not linked to a user such as [email protected], there is an “Unknown Sender Address” setting under the Web Interface > System > Outbound Control tab. By default it is set to “Reject Message”. If it is set to “Allow Message”, the Sendio ESP will accept outbound e-mail from unknown senders such as [email protected]. For […]
How do I route outbound e-mail through the Sendio ESP?
Configure your mail server to forward all outbound e-mail to the Sendio ESP. The feature is often referred to as “forwarding to a smart host”. Please refer to documentation for your e-mail server for instructions on how to configure and enable smart hosting. To set up the Sendio ESP to provide outbound e-mail processing navigate […]
What are the benefits of enabling outbound e-mail through the Sendio ESP? What is Auto-listing?
The main benefit of enabling outbound e-mail through the Sendio ESP is a feature we call auto-accept listing. Essentially, the Sendio ESP can “learn” about valid e-mail addresses as outbound e-mail goes through the appliance. These outbound e-mail addresses sent through the Sendio ESP will be added to the user Account Contact list, thus enacting […]
How do I set up the Sendio ESP to work with one or more hosted mail servers?
Your Sendio ESP can be configured to handle multiple domains for multiple customers. The Sendio ESP can forward e-mail for each customer to their mail server, whether they have one on premise (Exchange or other) or whether their e-mail is hosted by a mail hosting service. As an example, let’s assume we are setting up […]
How do I set up and verify Reverse DNS Lookup?
To ensure remote mail servers reliably accept SMTP connections from the Sendio ESP, first determine the public IP address associated with it and then ensure a corresponding PTR record is set up for this address. To determine the public IP address, access the Console (SSH) Interface > Network Diagnostics > SMTP Diagnostics Test. This server will respond […]
Is reverse DNS (rDNS) important?
Yes. Many mail servers will not properly accept or process email coming from IP addresses that fail a reverse DNS lookup. Please review this FAQ for instructions on setting up a reverse DNS entry – How do I set up and verify Reverse DNS Lookup?
Why are SAV Requests and other outbound e-mail being deferred or rejected?
Many mail servers perform a Reverse DNS lookup on the originating IP address of an incoming SMTP connection. If the result of such lookup fails or the result does not translate back to a proper hostname (one associated with your domain), the SMTP connection will either be rejected, the mail will be deferred, or it […]