SMTP

name

"smtp" is a 4-letter English headword indexed on PlainSpell.

The verdict

“SMTP” is uncommon English (frequency #65,510 among 6,566 “S” headwords), classed as a proper noun. The kind of spelling people second-guess.

#65,510
frequency rank, English
6,566
“S” headwords

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of Simple Mail Transfer Protocol, a de-facto standard for email transmission.

Corpus desk

Index EN-smtp · SMTP · English

SMTP · rank #65,510 · 0 variants · 0 confusables

  • FREQ-RARE #65,510
  • LEN-MID 4 letters
  • VOW-0 0 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-DENSE 6,566
  • PHOTO-FINISH Smolensk

Nearest frequency peer: Smolensk (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Long-tail ranks near “SMTP”

Sparse band: bars invert rank so rarer forms read shorter

corpus weight

What this shows Long-tail view: where “SMTP” sits against similarly uncommon English ranks.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for SMTP
PropertyValue
HeadwordSMTP
LanguageEnglish
Part of speechProper noun
Letters4
Frequency rank#65,510
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “SMTP” in English

This scale runs from the tiny cluster of words that carry ordinary speech (left) to the long tail of words almost nobody reaches for (right).SMTPfalls in this rarity band:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Rare peers in the same band: “Smolensk” (#65,509), “snowpack” (#65,511), “Smokies” (#65,508). Among 6,566 “S” headwords, “SMTP” is #65,510. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

SMTP is uncommon English at frequency #65,510 among 6,566 “S” headwords, classed as aproper noun. Rarity is why readers land here mid-draft. Gloss: "Initialism of Simple Mail Transfer Protocol, a de-facto standard for email transmission.".

Zero misspellings are on record for SMTP in our index, and the word's spelling is regular enough that our generator found nothing worth flagging. This entry stands alone in our confusable dataset, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Our source data has no etymology on file for this entry, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct English form is SMTP, spelled S-M-T-P.

Definition

  1. 1
    Initialism of Simple Mail Transfer Protocol, a de-facto standard for email transmission.

Recorded use

Wiktionary example

These source excerpts show how SMTP appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The objective of Simple Mail Transfer Protocol (SMTP) is to transfer mail reliably and efficiently.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "SMTP"?
"SMTP" is spelled S-M-T-P.
What does "SMTP" mean?
As a proper noun, "SMTP" means: Initialism of Simple Mail Transfer Protocol, a de-facto standard for email transmission.
What language does "SMTP" come from?
"SMTP" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "SMTP", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 4 letters (nearest by frequency rank).

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list