A website's readable news page is not necessarily an RSS or Atom feed. Thunderbird needs the publisher's feed endpoint, which may be linked from that page.

Establish what the publisher actually offers

Follow the publisher's RSS link. If it opens a category directory, choose the relevant feed from there; the directory page is not itself the subscription endpoint.

Note one recent public article that should appear in the chosen category, including its title and publication date. Also note a story from an unrelated category that should not appear. These two examples make an overly broad feed easier to recognise. Use these notes to decide whether the category covers the announcements your team actually needs to follow.

In Thunderbird, create a feed account through File, New, Feed Account if needed. Select that account, open Manage subscriptions, paste the endpoint into Feed URL and choose Add. Thunderbird validates the address and downloads the feed's current articles.

If validation fails, compare the entered address with the publisher's feed link. Renaming the Thunderbird account does not correct an unsuitable endpoint.

Check content and presentation separately

Open the resulting folder and compare its entries with the recorded examples. Check an article's title, date and destination before treating the subscription as the intended source. A feed may contain only recent entries; an absent old article is not proof that Thunderbird lost a complete website archive.

For a short feed extract, inspect View, Feed Message Body As. Summary shows the feed content; Web Page loads the article page, while Default Format follows the folder's choice. Decide which presentation suits the task before diagnosing a brief extract as missing text.

Use Get Messages to check for new entries when the publisher has added something relevant. Record the endpoint and the last article checked, rather than claiming that a successful first download proves future freshness. If the publisher stops updating or changes the endpoint, investigate its published feed information before creating duplicate subscriptions.

Sources: Thunderbird documentation.