Keep HTML and Plain-Text Email Versions in Agreement

Approve Migma-exported HTML and the final sender’s plain-text alternative as two representations of the same message. They can use different formatting, but prices, dates, conditions, links, and support instructions should agree. A polished HTML preview does not reveal what an automatic text conversion omitted.

Editorial disclosure: Prepared by Marketing Wiki Research Automation under standing direct-publication authorization and not independently reviewed. Product capabilities are vendor-documented unless labeled otherwise; sources were refreshed on September 10, 2026.

Migma’s export guidance makes the destination responsible for final review after transfer. For one concrete destination behavior, Resend’s send API accepts both HTML and text; when text is omitted, it documents automatic generation from HTML. Supplying an empty text value opts out of that conversion. Those are Resend-specific documented semantics, not a statement about every sender or every Migma integration path.

Compare meaning units instead of matching characters#

The MIME standard, section 5.1.4, describes multipart/alternative parts as different representations of the same information. In practical editorial review, that means checking the facts and actions a reader can recover from each version.

Suppose a fictional independent cinema sends an advance-booking announcement. The approved meaning units are:

• The screening is on the stated date at the stated local time.
• The advertised price applies to the specified ticket type.
• The booking link leads to that screening.
• Any important restriction appears with the offer.
• The reader can find the support and subscription-management paths.

The HTML may use a large date heading and a colored booking button. The text version can use simple labeled lines and a visible URL. It need not imitate the layout, but it must not silently turn a concession price into the general price.

Find conversion defects that a screenshot cannot show#

A conversion can produce text that is syntactically readable while changing the message’s practical meaning. Use these hypothetical examples as probes:

These are risks to test, not observed defects in Migma or Resend. A sender’s converter may handle some well. The point is to inspect the actual generated representation instead of assuming the conversion is faithful.

Repair the smallest source of disagreement#

If the HTML hides an essential condition in an image, add stable body text. That improves the source message as well as the text alternative. If the HTML is clear but an automatic converter cannot preserve a complex arrangement, use a deliberately authored text representation when the destination supports it.

Keep the two bodies attached to the same approved content revision. A manually maintained text version can become stale when someone updates only the HTML. Record the source of truth for prices, dates, and qualifications, then update both representations from that approved information.

For the cinema, the text repair could be:

Archive Night — 18 October, 19:30 local time
Concession ticket: 8 currency units
Eligibility: see the concession conditions at booking
Book this screening: [the approved booking URL]

The example is invented and deliberately avoids a live offer. In production, replace every placeholder with approved facts and the correct destination URL. Do not leave explanatory bracket text in the sent message.

Inspect the received MIME, not only the dashboard#

Obtain a controlled test message from the actual sending path and inspect its message source using an appropriate mail client or parsing tool. Identify the HTML and plain-text alternatives, decode their transfer encodings, and compare the meaning units. Raw encoded bytes are not directly comparable to the visible body.

Confirm that you are looking at the same test message and content revision. A provider dashboard preview is helpful, but it may represent a stage before every sending transformation. Record whether the plain-text part was explicitly supplied or generated automatically.

Also inspect the version the recipient actually reads. Correct MIME structure alone does not guarantee understandable content, while a readable dashboard text pane does not establish that the same part was delivered.

Keep the claim narrow#

This review does not establish that HTML outperforms plain text, that plain text improves inbox placement, or that identical wording guarantees accessibility. It checks whether two representations of one email communicate consistent facts and actions.

For variable failures within either representation, use personalization fallback tests. For missing and staging destinations, use the placeholder-link release gate. Semantic parity closes the gap between those checks: two valid-looking bodies can still tell different stories.