If you have sent email to a @mailsac.com address or a private domain hosted at Mailsac and it was not received, this document will help you find out why.
If the address you sent to ends in @mailsac.com and the message was not received it could be because of:
- The sender has blocked sending to @mailsac.com addresses
- Large message size. The max message size is 2.5MB
- Throttling by Mailsac. If you are sending a large volume of email, we may throttle the rate of incoming messages
- The sending SMTP service has a queue
- The sending domain, IP address, or receiving address is on the deny list
- The message may have been marked as spam by the Spam Filter.
Zero-Setup Private Domain (@mydomain.msdc.co)¶
The Zero-Setup Private Domains handle all MX record changes. You can start receiving email with virtually no setup. If you are still have problems receiving mail it could be because of:
Bring Your Own Domain (BYOD) Private Domain¶
The BYOD Private Domain requires MX record changes. For assistance in configuring the MX records see our BYODomain Configuration.
If you have changed your MX records to use in.mailsac.com and alt.mailsac.com and are not receiving mail. There are several potential causes:
Some services place restrictions on the size, type, rate, and quantity of email that can be sent.
GMail is not designed for sending bulk mail. The service places limits on the number of emails sent per day and the number of recipients.
Messages sent through SendGrid are often queued and may not be sent immediately.
Sending from a sendgrid.net address may be impacted by throttling. Many Mailsac customers use SendGrid. Until Sender Authentication is configured within SendGrid, emails will be sent from the sendgrid.net domain. Sending from sendgrid.net email address can cause delays in delivery because of the quantity of mail sent from sendgrid.net to mailsac.com. Email sent to a Private Address or a Custom Domain are throttled at a higher threshold. In order to ensure timely delivery it is recommended to configure sender authentication in SendGrid and use a private address or custom domain at Mailsac.
Whitelisting can be requested for:
- IP addresses or networks
- Sending domains
- Sending addresses
- Receiving domains
- Receiving addresses
Mailsac applies a spam filter to all incoming email.
In the single inbox view, a “spam” label appears in the subject line.
The Unified Inbox displays messages classified as spam in the “Spam” folder. Spam messages skip the inbox.
The spam filter can be controlled at an account level.
Including the following information will help us identify why you are not receiving mail.
- the IP address of your sending server
- the email addresses you are sending to, and/or the domain you are sending TO
- the from email addresses, and/or the domain you are sending FROM
- Time frames when messages were lost. A ball park is ok, like, “from 8am - 9am on Dec 3rd GMT we sent 100 messages and only 85 were received” or just “I tried sending 5 messages from 8am - 9am GMT Dec 3rd and none of them went through”