What is an exact limit of attachments that can be sent in a single message to Google Groups?

Question

Groups administrator FAQ says (emphasis mine):

Yes, the maximum size limit for messages sent to a group is 25 MB, including attachments (the normal Gmail limit). Group owners or managers can edit specific groups to set lower size limits. The default size for a message sent in Google Groups is 25 MB.

A moment ago I've tried to send a message to my own group, having four lines of plain text and a total of two attachments (PDF files) -- 13 009 kB + 3 427 kB (16 MB according to Windows). I was blocked from doing so with an error message that total size of message exceeds group limit.

What am I missing? Where is the remaining 9+ MB to really exceed mentioned group limit?

(I'm group creator / owner / admin and for sure I haven't set lower limit, simply due to the fact, that I don't even know, where such limit can be configured in group management panel)

Some side-notes and research effects:

1. An answer to this question says something about 4 MB limits per file, which is something totally new for me. Is this still an active limit (question asked in 2012, but answered this year) as I don't find even a trace of 4 MB limit in Groups administrator FAQ?

This would fit to my case as one of the attachments has 13 MB of size. But, again, I don't know, if that 4-MB-per-file limit really exists as this is something new to me.

2. Four years old comment to the very same question says that I can use an URL like this:

https://groups.google.com/forum/?fromgroups#!groupsettings/YOURGROUPNAME/information

However, after using it (with replaced correct group name) I can't find any size-limits-related setting in neither this or any other section of my groups configuration.

Answer 1

Short answer

According to several posts, the limit for individual file attachments is 4MB^1,2. There is no official documentation about this.

Explanation

It's usual that users get confused by the way that Google use the term "groups". as there are:

• Contacts groups in Gmail and Google Contacts
• Groups created from the G Suite admin console
• Google Groups, http://groups.google.com
• Google Groups for Business, http://groups.google.com/a/yourdomain.com

The referred Groups Administrator FAQ by the OP is about groups created from the G Suite admin console and about Google Groups for Business.

While Google Groups for Business and Google Groups are very similar, some features and limits are not the same. I.E. a Google Group for Business group administrator could change the message size limit while a Google Groups group administrator can't.

The Official documentation for Google Groups could be found at http://support.google.com/groups. The official documentation for Google Groups for Business is included in the G Suite Administrator Help. Both editions are in scope of the G Suit Help Forum - Google Groups Category.

Answer 2

The answer is quite simple. Even though Groups administrator FAQ says nothing about this, another limit of up to 4 MB per each attachment really exists, when posting to Google Groups.

Thus, example message posted to Google Groups with 10 files per up to 2 MB each will be successfully posted, because neither official (25 MB per message) nor unofficial (4 MB per file) limit is exceeded in this scenario.

While another example message with just 2 files but at least one having more than 4 MB or with as many files as you want having more than 25 MB total will not be posted to Google Groups.

EDIT: It seems that after only 24 hours since posting my answer is no longer valid. Yesterday, I've tried to post a message to Google Groups and failed on 2,7 MB and 3,1 MB attachments.

It looks like Google is intentionally not mentioning that per-attachment size limit in FAQ, because it seems to be changing / random / undetermined. Since each error message is heavily guarded by suggestions of using Google Drive instead, it may be part of strange Google marketing campaign.