For example for agent log* keys we have parameters MaxLinesPerSecond, BufferSend and BufferSize, which in general provide ability to control speed and size of bulk messages.
These options exist for purpose.

But if we consider zabbix_sender - there are no any way to control such things if send values as bulk data (-i input file).

It creates serious troubles because of a well know unresolvable limitation of zabbix server - ZBX-9201

It's suggested to add new parameters for sender:

-l --limit <values> If sending many values from an input file, Zabbix sender will batch them at the limit
values in one go (all values will be processed). Default is 250 values
-d --delay <milliseconds> Specify delay in milliseconds between values sending in batches when send from input file
Default is no delay

-l replaces hardcoded 250 to configurable parameter

Example usage:

# time ./zabbix_sender -z localhost -i /tmp/aaa
info from server: "processed: 3; failed: 0; total: 3; seconds spent: 0.000088"
sent: 3; skipped: 0; total: 3

real    0m0.003s
user    0m0.000s
sys     0m0.000s

# time ./zabbix_sender -z localhost -i /tmp/aaa -l 1
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000090"
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000036"
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000031"
sent: 3; skipped: 0; total: 3

real    0m0.007s
user    0m0.004s
sys     0m0.000s

# time ./zabbix_sender -z localhost -i /tmp/aaa -l 1 -d 500
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000031"
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000047"
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000089"
sent: 3; skipped: 0; total: 3

real    0m1.507s
user    0m0.000s
sys     0m0.000s

Suggested patch adds such features.