I have a distribution list with 101 email address that I use for this command
/usr/sbin/sendmail -bm -v -f'XXXX.SUPPORT@xy.com' -t < /tmp/mailGm8zV8
/tmp/mailGm8zV8:
MIME-Version: 1.0
From: XXXX.SUPPORT <XXXX.SUPPORT.NoReply@xy.com>
Subject: test
To: stefano.rXYZXYZi@xy.com; dummy.001-66751d212b69b@xy.com; dummy.002-66751d212b6a6@xy.com; dummy.003-66751d212b6a7@xy.com; dummy.004-66751d212b6a8@xy.com; dummy.005-66751d212b6a9@xy.com; dummy.006-66
751d212b6aa@xy.com; dummy.007-66751d212b6ab@xy.com; dummy.008-66751d212b6ac@xy.com; dummy.009-66751d212b6ad@xy.com; dummy.010-66751d212b6af@xy.com; dummy.011-66751d212b6b0@xy.com; dummy.012-66751d212b6
b1@xy.com; dummy.013-66751d212b6b2@xy.com; dummy.014-66751d212b6b3@xy.com; dummy.015-66751d212b6b4@xy.com; dummy.016-66751d212b6b5@xy.com; dummy.017-66751d212b6b6@xy.com; dummy.018-66751d212b6b7@xy.com
; dummy.019-66751d212b6b8@xy.com; dummy.020-66751d212b6b9@xy.com; dummy.021-66751d212b6ba@xy.com; dummy.022-66751d212b6bb@xy.com; dummy.023-66751d212b6bc@xy.com; dummy.024-66751d212b6bd@xy.com; dummy.0
25-66751d212b6be@xy.com; dummy.026-66751d212b6bf@xy.com; dummy.027-66751d212b6c0@xy.com; dummy.028-66751d212b6c1@xy.com; dummy.029-66751d212b6c2@xy.com; dummy.030-66751d212b6c3@xy.com; dummy.031-66751d
212b6c4@xy.com; dummy.032-66751d212b6c5@xy.com; dummy.033-66751d212b6c6@xy.com; dummy.034-66751d212b6c7@xy.com; dummy.035-66751d212b6c8@xy.com; dummy.036-66751d212b6c9@xy.com; dummy.037-66751d212b6ca@s
t.com; dummy.038-66751d212b6cb@xy.com; dummy.039-66751d212b6cc@xy.com; dummy.040-66751d212b6cd@xy.com; dummy.041-66751d212b6ce@xy.com; dummy.042-66751d212b6cf@xy.com; dummy.043-66751d212b6d0@xy.com; du
mmy.044-66751d212b6d1@xy.com; dummy.045-66751d212b6d2@xy.com; dummy.046-66751d212b6d3@xy.com; dummy.047-66751d212b6d4@xy.com; dummy.048-66751d212b6d5@xy.com; dummy.049-66751d212b6d6@xy.com; dummy.050-6
6751d212b6d7@xy.com; dummy.051-66751d212b6d8@xy.com; dummy.052-66751d212b6d9@xy.com; dummy.053-66751d212b6da@xy.com; dummy.054-66751d212b6db@xy.com; dummy.055-66751d212b6dc@xy.com; dummy.056-66751d212b
6dd@xy.com; dummy.057-66751d212b6de@xy.com; dummy.058-66751d212b6df@xy.com; dummy.059-66751d212b6e0@xy.com; dummy.060-66751d212b6e1@xy.com; dummy.061-66751d212b6e2@xy.com; dummy.062-66751d212b6e3@st.co
m; dummy.063-66751d212b6e4@xy.com; dummy.064-66751d212b6e5@xy.com; dummy.065-66751d212b6e6@xy.com; dummy.066-66751d212b6e7@xy.com; dummy.067-66751d212b6e8@xy.com; dummy.068-66751d212b6e9@xy.com; dummy.
069-66751d212b6ea@xy.com; dummy.070-66751d212b6eb@xy.com; dummy.071-66751d212b6ec@xy.com; dummy.072-66751d212b6ed@xy.com; dummy.073-66751d212b6ee@xy.com; dummy.074-66751d212b6ef@xy.com; dummy.075-66751
d212b6f0@xy.com; dummy.076-66751d212b6f1@xy.com; dummy.077-66751d212b6f2@xy.com; dummy.078-66751d212b6f3@xy.com; dummy.079-66751d212b6f4@xy.com; dummy.080-66751d212b6f5@xy.com; dummy.081-66751d212b6f6@
xy.com; dummy.082-66751d212b6f7@xy.com; dummy.083-66751d212b6f8@xy.com; dummy.084-66751d212b6f9@xy.com; dummy.085-66751d212b6fa@xy.com; dummy.086-66751d212b6fb@xy.com; dummy.087-66751d212b6fc@xy.com; d
ummy.088-66751d212b6fd@xy.com; dummy.089-66751d212b6fe@xy.com; dummy.090-66751d212b6ff@xy.com; dummy.091-66751d212b700@xy.com; dummy.092-66751d212b701@xy.com; dummy.093-66751d212b702@xy.com; dummy.094-
66751d212b703@xy.com; dummy.095-66751d212b704@xy.com; dummy.096-66751d212b706@xy.com; dummy.097-66751d212b707@xy.com; dummy.098-66751d212b708@xy.com; dummy.099-66751d212b709@xy.com; dummy.100-66751d212
b70a@xy.com
Content-Type: MULTIPART/mixed; charset="iso-8859-1"; BOUNDARY=4ea15edfb62daf8a1491f8d96d62a7a8
--4ea15edfb62daf8a1491f8d96d62a7a8
Content-Type: TEXT/plain; charset=us-ascii
Example Mail
.
For an unkown reason the distribution list is broken as "empty spaces" are inserted automatically on
Stefano RADAELLI <stefano.radaelli@xy.com>; dummy.001-66751d212b69b@xy.com; dummy.002-66751d212b6a6@xy.com; dummy.003-66751d212b6a7@xy.com; dummy.004-66751d212b6a8@xy.com; dummy.005-66751d212b6a9@xy.com; dummy.006-66751d212b6aa@xy.com; dummy.007-66751d212b6ab@xy.com; dummy.008-66751d212b6ac@xy.com; dummy.009-66751d212b6ad@xy.com; dummy.010-66751d212b6af@xy.com; dummy.011-66751d212b6b0@xy.com; dummy.012-66751d212b6b1@xy.com; dummy.013-66751d212b6b2@xy.com; dummy.014-66751d212b6b3@xy.com; dummy.015-66751d212b6b4@xy.com; dummy.016-66751d212b6b5@xy.com; dummy.017-66751d212b6b6@xy.com; dummy.018-66751d212b6b7@xy.com; dummy.019-66751d212b6b8@xy.com; dummy.020-66751d212b6b9@xy.com; dummy.021-66751d212b6ba@xy.com; dummy.022-66751d212b6bb@xy.com; dummy.023-66751d212b6bc@xy.com; dummy.024-66751d212b6bd@xy.com; dummy.025-66751d212b6be@xy.com; dummy.026-66751d212b6bf@xy.com; dummy.027-66751d212b6c0@xy.com; dummy.028-66751d212b6c1@xy.com; dummy.029-66751d212b6c2@xy.com; dummy.030-66751d212b6c3@xy.com; dummy.031 -66751d212b6c4@xy.com;
(a the end of this string)
dummy.032-66751d212b6c5@xy.com; dummy.033-66751d212b6c6@xy.com; dummy.034-66751d212b6c7@xy.com; dummy.035-66751d212b6c8@xy.com; dummy.036-66751d212b6c9@xy.com; dummy.037-66751d212b6ca@xy.com; dummy.038-66751d212b6cb@xy.com; dummy.039-66751d212b6cc@xy.com; dummy.040-66751d212b6cd@xy.com; dummy.041-66751d212b6ce@xy.com; dummy.042-66751d212b6cf@xy.com; dummy.043-66751d212b6d0@xy.com; dummy.044-66751d212b6d1@xy.com; dummy.045-66751d212b6d2@xy.com; dummy.046-66751d212b6d3@xy.com; dummy.047-66751d212b6d4@xy.com; dummy.048-66751d212b6d5@xy.com; dummy.049-66751d212b6d6@xy.com; dummy.050-66751d212b6d7@xy.com; dummy.051-66751d212b6d8@xy.com; dummy.052-66751d212b6d9@xy.com; dummy.053-66751d212b6da@xy.com; dummy.054-66751d212b6db@xy.com; dummy.055-66751d212b6dc@xy.com; dummy.056-66751d212b6dd@xy.com; dummy.057-66751d212b6de@xy.com; dummy.058-66751d212b6df@xy.com; dummy.059-66751d212b6e0@xy.com; dummy.060-66751d212b6e1@xy.com; dummy.061-66751d212b6e2@xy.com; dummy.062-6675 1d212b6e3@xy.com;
(and here)
dummy.063-66751d212b6e4@xy.com; dummy.064-66751d212b6e5@xy.com; dummy.065-66751d212b6e6@xy.com; dummy.066-66751d212b6e7@xy.com; dummy.067-66751d212b6e8@xy.com; dummy.068-66751d212b6e9@xy.com; dummy.069-66751d212b6ea@xy.com; dummy.070-66751d212b6eb@xy.com; dummy.071-66751d212b6ec@xy.com; dummy.072-66751d212b6ed@xy.com; dummy.073-66751d212b6ee@xy.com; dummy.074-66751d212b6ef@xy.com; dummy.075-66751d212b6f0@xy.com; dummy.076-66751d212b6f1@xy.com; dummy.077-66751d212b6f2@xy.com; dummy.078-66751d212b6f3@xy.com; dummy.079-66751d212b6f4@xy.com; dummy.080-66751d212b6f5@xy.com; dummy.081-66751d212b6f6@xy.com; dummy.082-66751d212b6f7@xy.com; dummy.083-66751d212b6f8@xy.com; dummy.084-66751d212b6f9@xy.com; dummy.085-66751d212b6fa@xy.com; dummy.086-66751d212b6fb@xy.com; dummy.087-66751d212b6fc@xy.com; dummy.088-66751d212b6fd@xy.com; dummy.089-66751d212b6fe@xy.com; dummy.090-66751d212b6ff@xy.com; dummy.091-66751d212b700@xy.com; dummy.092-66751d212b701@xy.com; dummy.093-66751d212 b702@xy.com;
(and here)
dummy.094-66751d212b703@xy.com; dummy.095-66751d212b704@xy.com; dummy.096-66751d212b706@xy.com; dummy.097-66751d212b707@xy.com; dummy.098-66751d212b708@xy.com; dummy.099-66751d212b709@xy.com; dummy.100-66751d212b70a@xy.com
Can anyone help me to understand why it happens and how to avoid it?
Quite likely you hit limit on maximum line length in email or maximum header length.
Alternative fixes to try:
To: (or 'Bcc:`) headers e.g. one header per one recipient