According to ICANN regulations, the Registrant contact of a domain should always receive a notification about the domain expiration. Details of the Expired Registration Recovery Policy (ERRP) can be found at:
http://www.icann.org/en/resources/registrars/consensus-policies/errp

To comply with this policy, we will automatically send domain expiration reminders to the Registered Name holders (the Registrant WHOIS contact) 26 days prior to the expiration, four days prior to the expiration, and in case of a non-renewal - a third notice five days after the expiration. These notices will be for the domain only, will be sent only to the Registrant contact, and this will not affect the current reminder schedule for hosting services (30/15/1 day prior, and 15 days after expiration).

For domains that are "non-resold" - e.g. domains of accounts marked as "resold own" in your Account Panel - expiration reminders will generally advise domain registrants to look for their account expiration notices, or to log in to their hosting Control Panels. For domains that are a part of "resold" hosting accounts, the expiration reminders will come from our technical support team and will advise Registered Name holders to contact their providers (you).

Our resellers have the option to stop these automatic domain renewal reminders for "resold" domains. This is done by selecting the option "I will send domain expiration reminders myself" on the "Account & Clients" > "My Account">"Options" section of the Account Panel.

IMPORTANT:
If you stop these reminders, it will be your sole responsibility to inform Registrant contacts of the domain expiry. Also, you must keep a log/copy of all reminders sent, as in case of a complaint at ICANN by the Domain Name holder, they will have to be provided to ICANN. In case of such a complaint, we will contact you, and within three days you should provide proof that the Registered Name holder has been informed about the domain expiry. Failure to provide such proof (logs, email copies) may result in proceedings against us as a provider, and you will be responsible for damages incurred by us and the Registered Name holder.

Opting-out of these automatic domain renewal reminders for "non-resold" domains is not possible.