Is 'spam' a countable or uncountable noun?
Summary
What email marketers say12Marketer opinions
Email marketer from Collins Dictionary explains that 'spam' is generally uncountable when referring to unsolicited emails. However, it can be used countably, especially when specifying types or instances of spam.
Email marketer from Email Geeks suggests not relying on French/German pages for proper English usage and notes that they have never heard "Spams" used in the plural in German.
Email marketer from WordReference Forums suggests that while 'spam' is generally uncountable, 'spams' could be used when referring to multiple, distinct instances or types of spam activity.
Email marketer from Email Geeks shares a link to wiktionary.org that says the plural of the noun "spam" is "spams".
Email marketer from Reddit explains that 'spam' is typically used as an uncountable noun but 'spams' can be used in informal contexts or when referring to different types of spam.
Email marketer from StackExchange shares that 'spam' is usually uncountable but can be countable when discussing distinct categories or examples of spam. Using 'spams' in this context emphasizes variety.
Email marketer from Email Geeks shares that they always use "spam" in the singular form, often paired with other words like "spam messages," "spam email," or "spam texts."
Email marketer from Merriam-Webster Dictionary explains that 'spam' can be both a countable and uncountable noun. As an uncountable noun, it refers to unsolicited electronic junk mail. As a countable noun, it can refer to a specific instance of spam or a type of spam.
Email marketer from Grammarly shares that the noun "spam" can be used as both countable and uncountable. As an uncountable noun it refers to general junk, but as a countable noun, it can be used to refer to individual instances of spam messages.
Email marketer from ProWritingAid explains that 'spam' functions mostly as an uncountable noun to refer to general instances of unsolicited electronic messages. However, using 'spams' is becoming increasingly common, and therefore acceptable.
Email marketer from Email Geeks shares that they usually use "spam emails" and have also never heard "spams" used in the plural in German.
Email marketer from Email Geeks points out that "spam" is also used as a verb, as in "They spammed me!"
What the experts say1Expert opinion
Expert from wordtothewise.com explains that whilst 'spam' as a term implies unsolicited emails, the countability is irrelevant. 'Spam' refers to messaging people did not ask for, and as a general term that has a negative connation.
What the documentation says3Technical articles
Documentation from Microsoft Support explains how to report spam or phishing emails in Outlook. It implicitly treats 'spam' as a general category (uncountable) while providing options to manage individual spam messages.
Documentation from Google Support details how Gmail's spam filters work to identify and filter spam. It refers to 'spam' as a general category, using the uncountable form. It details how individual messages are assessed.
Documentation from Spamhaus describes how they track and combat spam. The term 'spam' is generally used as uncountable to refer to unsolicited bulk email, whilst tracking individual spamming sources.