drweb blocking zipped excel file

[Herby]

Dear Postmaster,

the message with following attributes has not been delivered, because
contains an object which violates archive restrictions.

--- Dr.Web report ---
Dr.Web detailed report:
127.0.0.1 [20694] drweb.tmp.OCQiQO - archive MAIL
127.0.0.1 [20694] drweb.tmp.OCQiQO/[textlain] - Ok
127.0.0.1 [20694] drweb.tmp.OCQiQO/mz.zip - archive MAIL
127.0.0.1 [20694] >drweb.tmp.OCQiQO/mz.zip/html.1 - Ok
127.0.0.1 [20694] >drweb.tmp.OCQiQO/mz.zip/import-webseite.zip - archive ZIP
127.0.0.1 [20694] >>drweb.tmp.OCQiQO/mz.zip/import-webseite.zip/import-webseite.xls - file too large, skipped
127.0.0.1 [20694] drweb.tmp.OCQiQO/mz.zip - Ok

Dr.Web scanning statistic:
Archive restriction : 1

--- Dr.Web report ---


a) why is it blocked
b) how can I avoid this ?

btw - the file is clean but contains a self written macro for importing textfiles to excel.