What is MissinglettrBot?

MissinglettrBot is a bot in the advertising and marketing bots category, operated by Missinglettr.

Bot name
MissinglettrBot
Operator
Missinglettr
Type
Bot
Respects robots.txt
Not confirmed
robots.txt user agent
MissinglettrBot
Signs requests (Web Bot Auth)
No

About MissinglettrBot

Missinglettr will crawl specific blog posts on customers' sites to help turn them into social media campaigns.

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

MissinglettrBot user agent

MissinglettrBot identifies itself with this user agent string:

  • Mozilla/5.0 (compatible; MissinglettrBot/2.0; +http://missinglettr.com/bot/)

Anyone can copy a user agent string. Transfon Security also checks where each request comes from, so a request that claims to be a known crawler but comes from the wrong network is treated as a fake, not as the real crawler.

How to block MissinglettrBot in robots.txt

We have not confirmed whether MissinglettrBot follows robots.txt. Add a rule, then check your logs to see that it stopped. robots.txt is a plain text file at the root of your domain, such as https://example.com/robots.txt.

Block MissinglettrBot from the whole site

User-agent: MissinglettrBot
Disallow: /

Block MissinglettrBot from some folders

User-agent: MissinglettrBot
Disallow: /private/
Disallow: /search

Allow MissinglettrBot only on some folders

User-agent: MissinglettrBot
Allow: /blog/
Disallow: /

Allow MissinglettrBot and block other crawlers

User-agent: MissinglettrBot
Allow: /

User-agent: *
Disallow: /

Things to know

  • Each host needs its own file. Rules on www.example.com do not apply to shop.example.com.
  • A crawler obeys only the most specific group that names it. Once you add a User-agent: MissinglettrBot group, MissinglettrBot ignores your User-agent: * rules, so repeat any that should still apply.
  • The user agent name is not case sensitive. We take MissinglettrBot from MissinglettrBot's user agent; check Missinglettr's own documentation if it publishes a different robots.txt name.
  • Crawlers cache robots.txt, so changes can take up to a day to apply. Disallow stops crawling but does not remove pages already collected or indexed.

Limits of robots.txt

  1. MissinglettrBot may not follow the rule. robots.txt is a request that nothing enforces, and we have not confirmed that MissinglettrBot follows it. Check your logs after adding a rule.
  2. The user agent could be fake. robots.txt matches the name a request claims. Anyone can send MissinglettrBot's user agent, and a scraper using it is not bound by Missinglettr's robots.txt policy. Only checking the source network tells a real MissinglettrBot from a fake one.

Treat robots.txt as a statement of your policy, and enforce it where requests arrive.

Who should care about MissinglettrBot

Publishers

Ad verification and contextual crawlers like MissinglettrBot can decide whether your pages get demand. Blocking the ones your partners use can lower fill rates.

Transfon Security for publishers

Media buyers and advertisers

MissinglettrBot checks pages for ad platforms. Its visits to landing pages are not users, so exclude them from conversion data.

Transfon Security for advertisers

E-commerce

Ad platforms send crawlers like MissinglettrBot to check product landing pages. Keep it allowed so ads are not disapproved, and out of analytics.

Transfon Security for e-commerce

SaaS and APIs

Allow MissinglettrBot on landing pages linked from your ads, and keep it off the app.

Transfon Security for SaaS and APIs

Block MissinglettrBot with Transfon Security

robots.txt is a request, not an enforcement. Transfon Security shows MissinglettrBot by name in the Top Bots report, so you can see how often it visits and which pages it reads. Block or allow it with a User Agent rule, or slow it down with a rate limit decision rule.

Transfon Security

Control MissinglettrBot on your site

  • See every MissinglettrBot visit and the pages it reads
  • Spot bots that fake trusted crawler names
  • Block, allow or rate limit MissinglettrBot with one rule
  • Works with or without robots.txt support

Frequently asked questions

What is MissinglettrBot?

MissinglettrBot is a bot in the advertising and marketing bots category, operated by Missinglettr. Missinglettr will crawl specific blog posts on customers' sites to help turn them into social media campaigns.

Does MissinglettrBot respect robots.txt?

We have not confirmed whether MissinglettrBot follows robots.txt. Add a robots.txt rule, then check your logs to see that it stopped, and block it by user agent if it did not.

How do I block MissinglettrBot?

Add "User-agent: MissinglettrBot" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "MissinglettrBot" at your WAF. In Transfon Security that is one User Agent block rule.

Is robots.txt enough to block MissinglettrBot?

No. robots.txt is voluntary, so MissinglettrBot may not follow it, and anyone can send MissinglettrBot's user agent, so a fake MissinglettrBot ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.

Should I block MissinglettrBot?

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

Related bots

All advertising and marketing bots · Full bot directory

See Which Bots Visit Your Site

Transfon Security identifies every bot in this directory in your traffic reports, flags fake search crawlers, and lets you allow, block or rate limit each bot.

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