High CPU usage & geometrically increasing delay with increasing length of the recipient address

[jusiponen]

Measured with simple-java-mail-v2.1 and javax.mail-1.5.1

05-05-2015 16:53:48: Sending email: rekry@fi.xyz.dom -> iitakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom (3 attachments)
05-05-2015 16:53:48: These attachments were sent:
05-05-2015 16:53:48: Attachment 1 / 3 filename '108782_-_Sally-Ellen_Example.pdf', content type 'application/pdf'
05-05-2015 16:53:48: Attachment 2 / 3 filename '108782_Sally-Ellen_Example_108782_-_Ansioluetteloni.pdf', content type 'application/pdf'
05-05-2015 16:53:48: Attachment 3 / 3 filename '108782_Sally-Ellen_Example_108782_-_Hakemuskirje.pdf', content type 'application/pdf'
05-05-2015 16:55:57: DEBUG Mailer - starting mail session (host: null, port: null, username: null, authenticate: null, transport: SMTP_PLAIN)

05-05-2015 16:57:31: Sending email: rekry@fi.xyz.dom -> i-itakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom (3 attachments)
05-05-2015 16:57:31: These attachments were sent:
05-05-2015 16:57:31: Attachment 1 / 3 filename '108782_-_Sally-Ellen_Example.pdf', content type 'application/pdf'
05-05-2015 16:57:31: Attachment 2 / 3 filename '108782_Sally-Ellen_Example_108782_-_Ansioluetteloni.pdf', content type 'application/pdf'
05-05-2015 16:57:31: Attachment 3 / 3 filename '108782_Sally-Ellen_Example_108782_-_Hakemuskirje.pdf', content type 'application/pdf'
05-05-2015 17:01:20: DEBUG Mailer - starting mail session (host: null, port: null, username: null, authenticate: null, transport: SMTP_PLAIN)

05-05-2015 17:16:47: Sending email: rekry@fi.xyz.dom -> ki-itakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom (3 attachments)
05-05-2015 17:16:47: These attachments were sent:
05-05-2015 17:16:47: Attachment 1 / 3 filename '108782_-_Sally-Ellen_Example.pdf', content type 'application/pdf'
05-05-2015 17:16:47: Attachment 2 / 3 filename '108782_Sally-Ellen_Example_108782_-_Ansioluetteloni.pdf', content type 'application/pdf'
05-05-2015 17:16:47: Attachment 3 / 3 filename '108782_Sally-Ellen_Example_108782_-_Hakemuskirje.pdf', content type 'application/pdf'
05-05-2015 17:25:24: DEBUG Mailer - starting mail session (host: null, port: null, username: null, authenticate: null, transport: SMTP_PLAIN)

Summary

Email address	Addr. Length	Start (hh:mm:ss)	Finish (hh:mm:ss)	Time taken	Delta
iitakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom	48	16:53:48	16:55:57	0:02:09	n/a
i-itakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom	49	16:57:31	17:01:20	0:03:49	0:01:40
ki-itakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom	50	17:16:47	17:25:24	0:08:37	0:04:48
hki-itakeskus-kauppakeskus-rav.paallikko@fi.xyz.dom	51	DID NOT MEASURE -- This is the address that brought this problem to attention

I haven't verified with plain Java Mail if the problem persists.

[bbottema]

I think these might be regex related when validating the email addresses. In the next release (not scheduled yet), by default regex email address validation will be turned off.

[jusiponen]

Regexes sounds plausible, given the CPU/time double-whammy.

Any way to turn those checks off at runtime (let's assume we have validated all addresses previously)?

[bbottema]

Not yet. In the next release it will be turned off by default with the option to turn it on. Currently no workaround.

[jusiponen]

Ok, I'll take the sources and compile a private version for now.

Thanks!

[bbottema]

@jusiponen, I just released simple-java-mail 2.2 to maven central. Can you please have a go with it and see if the issue still persists?