Applications by mail are not permitted, though interviews may be waived for persons who have received US visas in the past as well as for government officials and certain other applicants. Those whose applications are accepted can expect to be interviewed and issued a visa approval or denial the same day. Most applicants are seeking tourist visas or student visas and consular officials are generally concerned about non-immigrant intent, especially for those who have never before been to the US and for younger applicants. Note that there is no limit on the number of times an applicant can apply nor is there a limit on the amount of time that must pass before an applicant can reapply. Interviews are typically scheduled within two months after a priority date becomes current and within three weeks after an immediate relative's Packet 3 is received by the consulate.
Visas are usually available within a week of satisfying all of the requirements.
The post generally prefers not to initiate processing instead of the National Visa Center. The visa refusal rate is higher than average generally because of a high rate of fraud, particularly fraud regarding the existence and termination of earlier marriages by the Bangladeshi applicant as well as false statements of age. Applications are also frequently denied for failure to meet public charge requirements.