My client have registered a domain name through BigRock.in, and my client needs 10 email accounts, so I decided to provide it through my web hosting (re seller account).
My question is - How to provide email accounts without changing the DNS?
Generally speaking these days in order to receive emails into mailboxes:
The domain name should have an MX record pointing to a FQDN (e.g.
mail.domain.com) which has an associated
A record resolvable to an IP address, and the SMTP dialogue would take place with the mail server behind that IP address.
In the event the domain name has no
MX records but does have an
A record which points to the mail server IP address then some mail servers when accepting outbound messages will open SMTP dialogue with the mail server and carry on as normal. However, many will not since it is now considered to be industry best practice to recognise that a domain with no MX records is to be observed as a domain which should not receive email (even though contrary to some early RFC's). While in some circumstances the web server may have shared roles and double up as a mail server, this is not always the case and should not be expected to be the case.
The email address may contain the mail server's public fixed IP address instead of a domain name (e.g.
email@example.com). With this scenario if you plan to send messages from the same email address you'll find the vast majority of anti-spam systems will stop them if a valid domain name and MX record do not exist.
If you cannot change the DNS and an existing
MX record exists that points to a different server you will have to make DNS changes, though this is normally a feature available in the control panel of the domain name registrar where the domain name was purchased or can be completed simply by opening a support ticket and a member of their staff will do this for you (this is not normally a chargeable request).
You perhaps should not rely on the domain name for any commercial use until you can control and change the DNS entries. This might be a good time to explore moving the domain name to another registrar if you don't have confidence you can change settings with the current registrar.
If there really is no option of recovering control over the domain name then it may be worth registering a new domain name with a registrar that does offer managed DNS and a control panel for making DNS changes.
Sorry but you either need to change the name server or MX records.
When using Domain based email regardless where they may be in the world you need some instructions on servers to let them know where the server is at, this is called MX Records. With no MX Records set there is no way of telling the email where to go.
To clear your question, lets suppose a scene.
You are a hosting reseller. Your main domain is > youreseller.com.
You sold a domain to client, that is yourclient.com.
And Now you want to create email address for yourclient.com domain in hosting control panel (cpanel or pleask) for youreseller.com.
This is not possible as per my knowledge without changing DNS records. If your client is asking for more email addresses, you can install any mailing software (RoundCube or other) in a subdomain of client's domain. Then point records towards that and get email working.
Or just point your Mail Exchange Records settings (MX) to Google App for 10 users using gmail with custom domain or domains.live.com for 50 users for free.
All the Best.
a. Identify FQDN of your host, which will be collector of mail for your client and (just for sake) it's IP
b. Add additional RR to client's domain root
@ IN MX <NN>YOUR.HOST.HAME, there NN - priority any positive value
@ IN A IP.OF.YOUR.HOST.HAME
c. Enable receiving e-mail in your MTA for domain, add user's mailboxes