Is Google applying SPF checks to EHLO values for stricter email authentication?

Marketer from Email Geeks confirms that checking HELO before MAIL FROM is recommended but doesn't imply priority if both have valid SPF records, quoting RFC7208.

Email marketer from Litmus states SPF and other authentication methods are important for getting to the inbox. EmailOnAcid further suggests that stricter adherence might include HELO checks.

Email marketer from MXToolbox explains that SPF records can be checked against both MAIL FROM and HELO. Some providers may prioritize HELO checks, especially when evaluating initial connection legitimacy.

Email marketer from EasyDMARC explains that SPF is crucial for identifying authorized mail servers. EasyDMARC suggests HELO checking is a valuable, although not universally implemented, method for validating sender identity.

Email marketer from Stackoverflow explains that some systems use EHLO/HELO for initial checks, and if the HELO/EHLO fails SPF, the mail might be rejected before even checking the MAIL FROM. This is an optimization to prevent further resource usage on bad connections.

Email marketer from Postmark explains that SPF helps prevent email spoofing. Though they don't explicitly mention checking HELO, their overview emphasizes the need for comprehensive authentication, implying HELO checks might be part of a stringent approach.

Marketer from Email Geeks advises fixing the PTR record as it's a common issue for Microsoft and even smaller spam filters.

Email marketer from AuthSMTP explains that EHLO/HELO is the first step in SMTP communication, and while SPF can be applied, its implementation for HELO varies. They note some systems may use it as an early filter.

Email marketer from Reddit suggests that while not universally enforced, HELO SPF checks are part of the SPF specification and some mail servers might use them as an additional check, especially when MAIL FROM SPF records are absent or inconclusive.

Marketer from Email Geeks states that spf_scope in aggregate reports indicates what receivers are checking, typically MAIL FROM.

Email marketer from Mailhardener Blog notes that checking the HELO/EHLO identity is recommended by the RFC, but might not be implemented by all ESPs. Some older systems might strictly adhere to it, while others focus more on MAIL FROM.

Email marketer from Validity's ReturnPath services touches upon the importance of domain reputation which gets impacted by authentication results. ReturnPath insinuates that increasingly granular authentication checks, potentially including EHLO analysis, would lead to a better overall reputation and thus deliverability.

Marketer from Email Geeks quotes RFC7208, recommending SPF verifiers check the HELO identity before MAIL FROM for consistency and reduced DNS usage.

Expert from Email Geeks mentions that the SPF spec dictates checking EHLO before Mail From.

Expert from Word to the Wise indicates that while MAIL FROM is the primary focus, HELO/EHLO checks do happen, and a mismatch or failure can impact deliverability. Word to the Wise stresses the HELO must be a valid, resolvable hostname.

Expert from Email Geeks explains that one authentication issue is when the PTR record shows a hostname that results in NXDomain.

Expert from Email Geeks suggests Google might be applying SPF to EHLO values or being stricter about FcrDNS due to reports of Google tightening authentication requirements.

Expert from Spam Resource explains that SPF HELO checks are increasingly important due to DMARC. With DMARC, domains have to be aligned to pass, and the HELO domain is often used for this alignment. This indirectly makes SPF HELO checks more relevant in the age of DMARC.

Documentation from SparkPost explains that SPF records validate the sending server's IP. While it doesn't explicitly mention HELO, their documentation encourages a thorough SPF setup which implies the possibility of stricter HELO checking.

Documentation from Microsoft Learn details that SPF records help validate the origin of email messages. While it doesn’t explicitly mention HELO checks, it emphasizes the importance of SPF in general, hinting that stricter adherence might include HELO checks as part of overall authentication.

Documentation from ietf.org explains that SPF verifiers are recommended to check the HELO identity, applying the check_host() function. Checking HELO can promote consistency and reduce DNS resource usage.

Documentation from Dmarcian highlights the importance of SPF in email authentication, mentioning the RFC recommendation to check HELO. Dmarcian implies that modern email receivers may be increasingly implementing stricter SPF validation processes including HELO analysis.

Documentation from Google explains that SPF helps prevent spammers from sending unauthorized messages using your domain. While it doesn't explicitly state HELO checks, it implies a focus on verifying the sender's IP address which is relevant to HELO evaluation.