Increase limit email Reroute

can you increase limit email size to 25 or 50 ?

Cloudflare’s Email Routing email size limit is already 25Mb.



what happen if i sent email to domain that use route email from CF more than 10MB
let say 15 MB attahment

15MB is less than 25 so unless that exceeds the receiving limit of your MTA it would be delivered?

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already upgraded not 10 anymore ?

it was 10 if im not wrong

now is 25MB ?

so if we sent 30MB it will Mailer Daemon with notification limitation email size or lost-in-space or only text will delivered w/o attachment ?

It’s 25Mb for the entire email including any attachements. If the email exceeds the size, it will be rejected by Cloudflare email routing service.


and as a sender it will Mailer-Daemon Exceeded notification ? or no notification ?

The receiving MTA, Cloudflare, will reject the message. The decision to return an NDR is that of the sending MTA. Cloudflare is not a sending MTA.

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sorry i can not understand well…

so the sender will not receive any mailed-daemon ?

The responsibility for sending a DSN is on the sending MTA. Since the sending MTA is not Cloudflare, Cloudflare is not responsible for sending anything. If the sending MTA would normally send an NDR it will send an NDR.

Cloudflare’s MTA will respond with the maximum size supported in the EHLO response of the sending MTA supports ESMTP and the sending MTA will generate the DSN. If the sending MTA is from last century, Cloudflare will respond with an error of the data sent exceeds the supported max, at which point, again the onus is on the sending MTA to send the NDR.

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You seem to want an answer as to what any random (likely Linux based) MTA will do. The answer is no one knows. Cloudflare’s SMTP proxy is reasonably RFC compliant. It’s impossible to say what a random sending MTA will do. If it doesn’t suck normally, it will still not suck.

@cscharff : if im not wrong to translate in english :smiley:

it will become like this:

A: Sender
B: Receiver (CF Reroute)

A Send to B 30MB Attachment
then because B using CF Email ReRoute then the email will never arrived at B’s Email.
and A will never get the Mailer-Daemon notification about that

correct me if im wrong
sry :newbie: here

If Cloudflare wasn’t involved, would the user receive a notice? If so they will with Cloudflare in place as an SMTP relay.

using internal corp email…

Then they would still receive a notice.

using internal corp email…

yes thankyou
i just test it…

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