Recently, Internet Service Providers have taken another step in trying to reduce the amount of fraudulent and spam emails sent to their customers. DMARC, short for Domain-based Message Authentication, Reporting, and Conformance, is a new security policy used for email authentication. DMARC standardizes how email servers perform email authentication using SPF(Sender Policy Framework) and DKIM(DomainKeys Identified Mail) mechanisms. In short, This new type of authentication checks the "From" email address to confirm the real sender of an email message.
Internet Service Providers enforcing DMARC policy include: Yahoo, AOL, Gmail, Microsoft networks(Hotmail, MSN, Outlook.com) and Comcast. If you use a Reply email address from one of these Internet Service Providers for Email marketing campaigns with your Email Marketing Provider, your messages will likely be rejected.
Using a Reply email address from these providers to send campaigns from your Email Marketing Provider's servers will now be seen as an attempt to pose as the Internet Service Provider, a process known as phishing or spoofing.
With good email marketing practices you will not be affected by these changes.
The Reply email address used for email marketing should be a valid, monitored email from a domain that you control. Preferably a domain that is associated with your organization or website. This is good for branding and familiarity. Newsletter@yourwebsite.com or FlashDeals@yourwebsite.com are good examples of an Reply email that not only maintain branding, but also describe the purpose of your mailing.
Don't use firstname.lastname@example.org. Your recipients should be able to reply to you. A "no-reply" Reply email discourages that. You are basically saying "Read my email, but I don't want to hear from you". This goes against engaging the reader and building customer relationships, which is what email marketing is all about.
Also, Using other free email address providers is not the answer and should be avoided. They will likely start enforcing the same policy. If you don't know how to get an email address for a domain you control, contact your IT staff or domain registrar, such as GoDaddy, 1&1 or Register.com.