Does Ignition have a file size limit for email attachments?

Module Development
1

Hi everyone,

I'm working with Ignition 8.1.38, and I have a scheduled script that exports a .csv file (around 10 MB) and sends it via email using an Office365 SMTP profile (smtp.office365.com, port 587, STARTTLS).

During testing, the script worked perfectly. However, on one scheduled run, it failed with the following error:

com.sun.mail.smtp.SMTPSendFailedException: 552 5.3.4 Message size exceeds fixed maximum message size at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1316) at javax.mail.Transport.send0(Transport.java:255)

What's strange is:

  • The file is only ~10 MB uncompressed, which should be well within Office365's limits.
  • The same script worked correctly before and after that failure.
  • Our mail server does not appear to have any size restrictions configured.

I understand that Ignition uses javax.mail (JavaMail) under the hood, and this looks like an error bubbling up from that layer.

Does Ignition itself impose any undocumented size limit on email attachments or outbound messages?

Could it be related to Java heap size, internal SMTP buffer, or timeout settings?

Any insights or similar experiences would be greatly appreciated.

Thanks in advance!

2

All of the references I can find say that message is from your mail server, not from Ignition. Presumably, Office365 is some flavor of Exchange, and there are numerous mentions of Exchange have a fixed 10MB size limit.

Perhaps you should fire Microsoft?

3

Just verified in the code that we do not.

I agree with Phil that this error is coming from your mail server. The error you see is coming from the mail server to Java, and we're just reporting what we got.