Email Service FAQ
Email Service FAQ
What types of email service do you provide?
We provide 5 different kinds of email service : Email Backup, Email Forward, Email Store/Forward, Full Service Email and SMTP Outbound Relay (Smarthost). Email Backup, Email Forward, Email Store/Forward and SMTP outbound relay cost $9.99/year, and Full Service Email $19.99/year.
My email server occasionally goes down and I am worried that I might lose emails during the downtime, which email service should I use?
You may choose Email Backup . After your ETRN host and port are set up in the control panel, our email server will receive emails for you and keep trying to forward email to your backup email server every 10 minutes (this retry interval can be set by you). This way your emails can never be lost.
Does your email service provide spam filtering?
Yes, all emails coming into our network are scanned for viruses. Many users sign up for our email service just for filtering spams.
What are IMAP, POP3 and SMTP?
SMTP, POP3 and IMAP are TCP/IP protocols used for mail delivery. Each protocol is a specific set of communication rules between computers.
SMTP(Simple Mail Transfer Protocol) is used when email is delivered from an email client(e.g. Outlook) to an email server or when email is delivered from one email server to another. SMTP uses port 25.
POP3 (Post Office Protocol) allows an email client to download an email from an email server. The POP3 protocol is simple and does not offer many features except for download. Its design assumes that the email client downloads all available email from the server, deletes them from the server and then disconnects. POP3 normally uses port 110. If you want to check your email using several email clients, POP3 is not advised.
IMAP (Internet Message Access Protocol) shares many similar features with POP3. It is also a protocol that an email client can use to download email from an email server. However, IMAP protocol is designed to let users keep their email on the server. IMAP requires more disk space on the server and more CPU resources than POP3, as all emails are stored on the server. IMAP normally uses port 143.
How does POP3, IMAP, SMTP protocols work?
Suppose you use Dynu mail server as your email server to send an email to firstname.lastname@example.org. You send email from your email client (Apple Mail), and Apple Mail delivers the email to Dynu mail server using SMTP protocol. Dynu mail server delivers the email to Outlook's mail server, mail.outlook.com using SMTP. John's email client (Thunderbird) downloads the email from mail.outlook.com to his computer using the POP3 protocol (or IMAP).
What is Email Backup?
Email Backup is a mail queueing system. Our server accepts email destined for your domain. We will hold all emails for you if we cannot deliver it to your mail server(offline due to maintenance or internet downtime). When your mail server comes back online, the emails will be dequeued from our system and delivered to you. We also perform SPAM filtering on Email Backup service.
My email server went down and now has just come back online, how long does it take to receive the emails queued in your server?
Our mail servers run on a schedule where they will attempt to deliver your email at the next scheduled interval. This interval is normally 10 minutes. You can also set it to a longer a shorter interval. If your email server has already come online and your emails are queued on our server, you may request our email servers to resend the emails immediately. All this can be done via the control panel.
I do not have Email Backup service, what happens to the emails when the email server is down?
There are 2 categories of e-mails based on their direction of flow: Incoming and Outgoing. In both directions to avoid the problems due to downtime of any server, there is a retry interval which can be from few minutes or an hour or so depeding on how the server is configured . There is also maximum retry duration which is normally 12-24 hours and if after that time sending server is unable to send the e-mail, it sends the sender an undeliverable report.
If you are the sender of the e-mail
If you do not receive an undeliverable report, it means the message is not lost and you do not need to resend the message.
If you are the receiver of the e-mail
In case you have not received an e-mail that you are supposed to receive, you might receive it with a delay or if the maximum retry duration has already expired and the sender has got the undeliverable report, sender is supposed to send you the e-mail again.
I am using your Email Backup. What MX records should I use ?
You may use mx1.dynu.com and mx2.dynu.com a secondary MX record so that when your mail server is unaccessible, our mail servers will receive your mails for you.
What can I use Email Forward service for?
With Email Forward service, you can accept and forward mail without needing to run your own mail server. For Example, you run a small business and own a domain name yourbusiness.com, you would like to receive emails for email@example.com, firstname.lastname@example.org, email@example.com. After signing up for Email Forward for your domain name, all you need to do is provide a catch-all email address that will receive all the emails sent to **@yourdomain.com accounts.
Can I send out emails from **@mydomain.com using your Email Forward service?
Email Forward service is only to receive emails for you. If you want to send out emails from **@mydomain.com and manage a list of email accounts, you should sign up for Full Service Email.
What MX records should I use to use your Email Forward service?
You must use mx1.dynu.com and mx2.dynu.com as your primary mail servers so that all the emails destined for yourdomain.com will be received by our mail servers and forwarded to you
I host my own email server, but am not able to receive emails on port 25, what service should I use
You should use email store/forward service to receive emails on a port other than port 25.
I want a relay server to act as smart host for my MS Exchange server, can I use email store/forward service?
No, email store/forward service will only help you receive emails on an alternative ports. To send out emails uing our relay server, you should use SMTP outbound relay service.
SMTP Outbound Relay
I have purchased SMTP outbound relay service, what should my settings be?
Relay server: relay.dynu.com
Password: default password is your Dynu account password. You may also change it in the control panel.
Do you offer a trial account for SMTP outbound relay service?
Due to possible abuse of the trial account, we do not offer free trial accounts. Plus our SMTP outbound relay service works! If you find the service unsatisfactory and you did not abuse the service, we can provide a full refund within 14 days of your purchase.
What is your relay limit?
SMTP outbound relay allows you to send emails through our servers. To prevent spam, we limit our email accounts to 200 SMTP relays per day which let you send 200 emails from your email address on a daily basis. Your account will be temporarily disabled if it exceeds the limit. You can upgrade your account to increase this limit at any time.
What SPF records to use to include mail relay IPs?
If your domain name already has an SPF record, you need to include the following string to your existing record:
For example, your SPF record may look like v=spf1 a:relay.dynu.com ~all. You may use our SPF record generator to generate your SPF record. To check the current SPF reocrd for your domain name, you may use this.
Some of the emails I relayed using your email servers go into SPAM folder.
There are many possible reasons why an email is marked as SPAM. Our service could be abused but we maintain a list of usable IPs and switch to the new IP address if blacklisted. To prevent the emails going into the SPAM folder, you need to make sure that you include include: dynu.com in your SPF record
What configurations need to be done on my email client or email server to use SMTP outbound relay?
You will be provided with login to our SMTP server relay.dynu.com after you sign up for the service. You may do the following to set up your email server or client:
1. Use relay.dynu.com as outgoing SMTP server 2. Enable 'Outgoing SMTP server requires authentication' 3. Use the login username and password
If your ISP blocks outbound SMTP port 25, you may use port 2525, 26, 587 or 465 instead.
Full Service Email
Why should I use a domain-based email addresses(e.g. firstname.lastname@example.org)?
A domain-based email address, like email@example.com, gives you a more professional appearancewith customers and promotes your website and company. According to a marketing survey, customers are 9 times more likely to choose a company with a professional email address. Owning a domain based email address means you are putting your company in front of your customers every time you send out an email. Customers will be drawn to your website.
With our Full Service Email, it is as simple as signing up with your domain name. You can create unlimited email accounts such as firstname.lastname@example.org, email@example.com, firstname.lastname@example.org etc.
I have more than 1 domain names. Do I need a full service email for each domain ?
Yes. The mail services are domain based and one service is needed for each domain that you intend to use it with. For example, if you have yourdomain1.com and yourdomain2.com and need receive and send emails for both of them, you would have to sign up for Full Service Email for each one of the domains.
I use your Full Service Email, how do I configure my email client for **@mydomain.com?
You may refer to email client configuration tutorials. All common email clients such as Thunderbird, Apple Mail, Outlook are included.
What are the Mx records that I need to set up?
Please set up the following MX records for your domain name and give them high priority (lower value).
Primary : mx1.dynu.com
Secondary : mx2.dynu.com