Why is the GPT v2 dashboard showing SPF/DKIM errors when other data sources are not?
Summary
What email marketers say8Marketer opinions
Email marketer from Mailgun answers that SPF checks the domain of the envelope MAIL FROM address against the sending IP address. When messages are forwarded, the sending server is usually not authorized to send on behalf of the MAIL FROM domain, and the SPF check will fail.
Email marketer from LinkedIn answers that any bugs found within GPT should be reported, so that they can resolve them.
Email marketer from Quora answers that GPT v2 could have more aggressive thresholds than other systems. It marks emails as failing which others would not.
Marketer from Email Geeks suggests taking GPT v2 data with a grain of salt if other data points indicate everything is okay, implying v2 might be buggy.
Email marketer from EmailGeekForum suggests that GPT v2 and other sources might use different SPF/DKIM validation methods, especially regarding forwarded emails, leading to differing results.
Email marketer from Reddit suggests that Google Postmaster Tools v2 is new and might have bugs causing discrepancies with other data sources. He recommends relying on more established tools.
Email marketer from Stackoverflow suggests that GPT v2 might be showing domain-level issues, whereas other reports focus on subdomains. This could reveal unauthenticated mail streams.
Email marketer from SparkPost answers that DMARC validation can be complex and nuanced, with variations in interpretation across different email providers. GPT v2 could have stricter validation rules.
What the experts say4Expert opinions
Expert from Email Geeks shares the GPT compliance dashboard needs work and doesn't think the client will get punished for forwarded/weird mail failing, suggesting the dashboard can be confusing.
Expert from Word to the Wise (Laura Atkins) explains that deliverability tools (like GPT) have to make educated guesses about the data they are working with. They are never 100% accurate, and use different algorithms which can mean discrepancies.
Expert from Email Geeks shares that they get the same SPF error for EmailKarma, even with valid SPF/DKIM, suggesting it might be a bug in GPT.
Expert from Spam Resource (John Levine) explains that SPF failures are extremely common when email is forwarded. This is because the forwarder isn't authorized to send mail for the original sender's domain.
What the documentation says4Technical articles
Documentation from dmarc.org explains that SPF is prone to failing when emails are forwarded, because the originating IP address no longer matches the SPF record of the sending domain.
Documentation from Google explains that Google Postmaster Tools data is subject to delays. Discrepancies might arise if comparing to real-time data from other sources.
Documentation from DKIM answers that DKIM signatures can fail if email headers are stripped or modified during forwarding, even if DKIM was initially valid.
Documentation from RFC Editor details how DMARC policies work, stating that reporting is domain based. Implementers may not have reporting by subdomain.