Engineering Notes

SPF, DKIM, and DMARC together — why the missing DMARC record was blocking registration emails

SPF, DKIM, and DMARC together — why the missing DMARC record was blocking registration emails Background Registration confirmation emails were not reliably reaching users on Gmail and Outlook outside Japan — sometimes landing in spam, sometimes not arriving at all. Investigation pointed to a single root cause: the wpmm.jp domain had SPF and DKIM configured, but no DMARC record. What each of the three does SPF (Sender Policy Framework) declares in DNS which IP addresses are authorized to send mail for a domain. Receiving servers check the sending IP against the SPF record to confirm the source is legitimate. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to the message …

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Engineering Notes

The cp932 crash in the build gate that only happened on Windows — static detection, behavioral testing, and a negative check

The cp932 crash in the build gate that only happened on Windows — static detection, behavioral testing, and a negative check The symptom During the Windows build for v1.6.11, the build gate reported “version number consistency check failed.” But the version numbers were correct everywhere. The real cause was not a version mismatch. The build gate in build_app.py calls tools/bump_version.py via subprocess and checks its exit code. The success messages in bump_version.py contained emoji (✅ and similar). On Japanese Windows, the default code page is cp932, which cannot encode those characters. Python raised a UnicodeEncodeError on the very first write to stdout, the process exited non-zero, and the build gate …

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WordPress Maintenance

The excluded-plugin setting that Playwright ignored — fixing browser-mode updates and false residual warnings

The excluded-plugin setting that Playwright ignored — fixing browser-mode updates and false residual warnings The symptom In browser-mode maintenance (Playwright, no SSH), plugins marked as “excluded from update checks” were still being updated. After the run, a “plugin updates remaining” WARNING email arrived every time. The excluded plugins were intentionally left behind, but the residual check treated them as unfinished updates and fired a warning — a two-part problem: wrong behavior and a misleading alert. SSH path vs. Playwright path On SSH-capable sites, WP-CLI’s –skip-plugins flag carries the ignored_plugins list into the update command. That path already excluded them correctly. The Playwright path was different. browser_update_remaining_plugins() worked by clicking the …

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Engineering Notes

Site list scrolls to top on every delete — fixing the missing keepScroll argument across 6 call sites

Site list scrolls to top on every delete — fixing the missing keepScroll argument across 6 call sites The symptom Every time a site was deleted from the WordPress Maintenance Manager site list, the page jumped back to the very top. In environments managing many sites, removing an item in the middle of the list forced users to scroll back down before they could act on the next one. The same behavior occurred in five other operations: drag-and-drop reordering, thumbnail fetching (running behind an open modal), category deletion, tag deletion, and after maintenance completion. Root cause: omitting the keepScroll argument The fetchSites() function accepts two arguments: keepPage and keepScroll. When …

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