FME Server sending a huge amount of emails

Every feature that passes through the emailer transformer will send one email. So if 1000 features go through the transformer you'll get 1000 emails. It sound like this may have been the cause

The run that produced all the emails had the same number of features as any other run. This process runs every 5 minutes and only did this once.

are you able to share the job log? if not, see if you can see a line similar to this (referencing Emailer rather than the Logger)

This will give an indication as to how many features passed through the transformer

Here is the log file

A screenshot of your workspace would help us to try and nail this down, but it does seem to be that for whatever reason the Emailer(s) in your workspace process around 1000 features, a @hkingsbury​ pointed out: each feature is an email being sent.

I'd recommend you take a real close look to your workspace and also the specific data that caused this many emails to be sent.

Thanks for sending that through, looking at the log I can see the following,

Emailer__Mapping sent 407 emails

Emailer_Acquisition sent 555 emails

Emailer_Survey sent 138 emails

Emailer_Crossings_3 sent 16 emails

Emailer_Crossings_4 sent 44 emails

Emailer_Appraisal sent 15 emails

The other Emailers sent no emails.

As mentioned, the emailer will send one email for every feature that gets passed through it. In this instance 1175 features passed through emailers.

I'm assuming that you're wanting to send one email per run with a summary of any changes?

In the simplest form you can achieve this by replacing all your current Emailers with StatisticCalculators. Use these to calculate the total count of features. This would result in one feature with an attribute containing the value of 407 (Mapping) another feature with 555 (Acquisition) etc.

Then connect all the StatCalcs to an Aggregator, making sure of two things:

1. The 'sum' attribute from each StatCalc have different names
2. set Accumulation Mode in the Aggregator to 'Merge Incoming Attributes'

Out of the Aggregator you'll have one feature, with a bunch of different attributes containing the total sum of each part of the process. This can then be passed into an Emailer and configured to send you the results of the run. In this instance, you will only get at most one email per run.