So I managed to capture the IMAP session on my private setup at home when the attachment didn't load:
========== CUT ===========
- 4296 FETCH (UID 79319 INTERNALDATE "19-Dec-2024 08:45:58 +0100" RFC822.SIZE 4833363 FLAGS (\Recent) BODY[HEADER] {2013} Delivery-date: Thu, 19 Dec 2024 08:45:58 +0100 Received: from company.nl ([2001::]:37117) by l............... A33 OK Fetch completed (0.006 + 0.000 + 0.005 secs). A37 UID FETCH 79319 (UID RFC822.SIZE BODYSTRUCTURE)
- 4296 FETCH (UID 79319 RFC822.SIZE 4833363 BODYSTRUCTURE ((("text" "plain" ("charset" "UTF-8" "format" "flowed") NIL NIL "7bit" 628 20 NIL NIL NIL NIL)("text" "html" ("charset" "UTF-8") NIL NIL "quoted-printable" 14902 273 NIL NIL NIL NIL) "alternative" ("boundary" "------------5EXWg0Iu8dW8o3YRD7dph7JE") NIL NIL NIL)("application" "octet-stream" ("name" "Kersteditie2024.pdf") NIL NIL "base64" 4815062 NIL ("attachment" ("filename" "Kersteditie2024.pdf")) NIL NIL) "mixed" ("boundary" "------------0gFkVYGlMESirTIQU37JNRX9") NIL ("en-US") NIL)) A37 OK Fetch completed (0.001 + 0.000 secs). A38 UID FETCH 79319 (UID BODY.PEEK[1]<0.393216>) A39 UID FETCH 79319 (UID BODY.PEEK[1]<393216.393216>) A40 UID FETCH 79319 (UID BODY.PEEK[1]<786432.393216>) A41 UID FETCH 79319 (UID BODY.PEEK[1]<1179648.393216>) A42 UID FETCH 79319 (UID BODY.PEEK[1]<1572864.393216>) A43 UID FETCH 79319 (UID BODY.PEEK[1]<1966080.393216>) A44 UID FETCH 79319 (UID BODY.PEEK[1]<2359296.393216>) A45 UID FETCH 79319 (UID BODY.PEEK[1]<2752512.393216>) A46 UID FETCH 79319 (UID BODY.PEEK[1]<3145728.393216>) A47 UID FETCH 79319 (UID BODY.PEEK[1]<3538944.393216>)
- 4296 FETCH (UID 79319 BODY[1]<0> {15834} --------------5EXWg0Iu8dW8o3YRD7dph7JE Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit
Geachte lezer,............... --------------5EXWg0Iu8dW8o3YRD7dph7JE Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
<!DOCTYPE html> <html> <hea............ --------------5EXWg0Iu8dW8o3YRD7dph7JE-- )
- 4296 FETCH (UID 79319 BODY[1]<393216> {0} )
- 4296 FETCH (UID 79319 BODY[1]<786432> {0} )
- 4296 FETCH (UID 79319 BODY[1]<1179648> {0} ) A38 OK Fetch completed (0.006 + 0.000 + 0.005 secs). A39 OK Fetch completed (0.002 + 0.000 + 0.001 secs). A40 OK Fetch completed (0.001 + 0.000 secs). A41 OK Fetch completed (0.001 + 0.000 secs).
- 4296 FETCH (UID 79319 BODY[1]<1572864> {0} )
- 4296 FETCH (UID 79319 BODY[1]<1966080> {0} )
- 4296 FETCH (UID 79319 BODY[1]<2359296> {0} )
- 4296 FETCH (UID 79319 BODY[1]<2752512> {0} ) A42 OK Fetch completed (0.002 + 0.000 + 0.001 secs). A43 OK Fetch completed (0.002 + 0.000 + 0.001 secs). A44 OK Fetch completed (0.001 + 0.000 secs). A45 OK Fetch completed (0.001 + 0.000 secs).
- 4296 FETCH (UID 79319 BODY[1]<3145728> {0} )
- 4296 FETCH (UID 79319 BODY[1]<3538944> {0} ) A46 OK Fetch completed (0.001 + 0.000 secs). A47 OK Fetch completed (0.001 + 0.000 secs). ========== CUT ===========
I did remove the actual message data from the fragment above. Now when I shutdown the app on my phone and restart it, tapping the message again and then on the attachment, it successfully downloaded the attachment. This is a the fragment of the captured IMAP session without the actual data of the attachment:
========== CUT =========== A36 UID FETCH 79328 (UID RFC822.SIZE BODYSTRUCTURE) A33 OK Idle completed (2.245 + 2.245 + 2.244 secs).
- 4295 FETCH (UID 79328 RFC822.SIZE 4833363 BODYSTRUCTURE ((("text" "plain" ("charset" "UTF-8" "format" "flowed") NIL NIL "7bit" 628 20 NIL NIL NIL NIL)("text" "html" ("charset" "UTF-8") NIL NIL "quoted-printable" 14902 273 NIL NIL NIL NIL) "alternative" ("boundary" "------------5Xw8ldQiQkqLE7H0VdtAAAQM") NIL NIL NIL)("application" "octet-stream" ("name" "Kersteditie2024.pdf") NIL NIL "base64" 4815062 NIL ("attachment" ("filename" "AllichtHoornKersteditie2024.pdf")) NIL NIL) "mixed" ("boundary" "------------o0KKQGwxtQLV6Bq9NgmPHlIh") NIL ("en-US") NIL)) A36 OK Fetch completed (0.005 + 0.000 + 0.004 secs). A37 UID FETCH 79328 (UID BODY.PEEK[2]<0.393216>) A38 UID FETCH 79328 (UID BODY.PEEK[2]<393216.393216>) A39 UID FETCH 79328 (UID BODY.PEEK[2]<786432.393216>) A40 UID FETCH 79328 (UID BODY.PEEK[2]<1179648.393216>) A41 UID FETCH 79328 (UID BODY.PEEK[2]<1572864.393216>) A42 UID FETCH 79328 (UID BODY.PEEK[2]<1966080.393216>) A43 UID FETCH 79328 (UID BODY.PEEK[2]<2359296.393216>) A44 UID FETCH 79328 (UID BODY.PEEK[2]<2752512.393216>) A45 UID FETCH 79328 (UID BODY.PEEK[2]<3145728.393216>) A46 UID FETCH 79328 (UID BODY.PEEK[2]<3538944.393216>)
- 4295 FETCH (UID 79328 BODY[2]<0> {393216} JVBERi0xLjQKJeLjz9MKMSAwIG9iago8PAovQ3JlYXRpb25EYXRlIChEOjIwMjQxMjEzMDcy MTIxKzAxJzAwJykKL0NyZ................. ....eHJlZgozNDcxMDMwCiUlRU9GCg== )
- 4295 FETCH (UID 79328 BODY[2]<5111808> {0} )
- 4295 FETCH (UID 79328 BODY[2]<5505024> {0} ) A49 OK Fetch completed (0.003 + 0.000 + 0.002 secs). A50 OK Fetch completed (0.002 + 0.000 + 0.001 secs). A51 OK Fetch completed (0.001 + 0.000 secs).
- 4295 FETCH (UID 79328 BODY[2]<5898240> {0} ) A52 OK Fetch completed (0.001 + 0.000 secs). ========== CUT ===========
So yes, it must be a client issue, but it only seems to appear on dovecot imap servers. I've tested this on my private setup at home with Dovecot 2.3.19.1 from Debian 12 repository as well as at the company where we use Dovecot-ee 2.3.21-8 from the Open-xchange repository where the same happens.
Regard, Frido
Op 18-12-2024 om 12:25 schreef via dovecot:
This is clearly a problem with the mail client on iPhone.